Affiliations
Division of Endocrinology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
Given name(s)
Catherine L.
Family name
Liang
Degrees
MPH

Improving Inpatient Glycemic Control

Article Type
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Sun, 05/28/2017 - 21:59
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Effects of a subcutaneous insulin protocol, clinical education, and computerized order set on the quality of inpatient management of hyperglycemia: Results of a clinical trial

Diabetes mellitus and/or inpatient hyperglycemia are common comorbid conditions in hospitalized patients. Recent surveys show that over 90% of hospitalized diabetic patients experience hyperglycemia (>200 mg/dL), and in nearly 1 in 5 of these patients hyperglycemia persists for 3 days or more.1 Hyperglycemia among inpatients without a previous history of diabetes mellitus is also very common.2 Observational studies have shown that hyperglycemia in hospitalized patients is associated with adverse outcomes including infectious complications, increased length of stay, and increased mortality.27 Recent randomized controlled trials have demonstrated that aggressive treatment of inpatient hyperglycemia improves outcomes in surgical and medical intensive care units.8, 9

Based on the available data, the American Diabetes Association (ADA) now advocates good metabolic control, defined as preprandial glucose levels of 90 to 130 mg/dL and peak postprandial glucose levels <180 mg/dL in hospitalized nonintensive care unit (ICU) patients.10 To reach these targets, the ADA and American College of Endocrinology (ACE) suggest that multidisciplinary teams develop and implement hyperglycemia management guidelines and protocols.11 Protocols should promote the use of continuous intravenous insulin infusions or scheduled basal‐bolus subcutaneous insulin regimens. Subcutaneous insulin protocols should include target glucose levels, basal, nutritional, and supplemental insulin, and daily dose adjustments.6 A recent randomized controlled trial of non‐ICU inpatients demonstrated that such a basal‐bolus insulin regimen results in improved glucose control compared with a sliding scale only regimen.12

To date, few published studies have investigated the best ways to implement such management protocols; those that have are often resource‐intensive, for example involving daily involvement of nurse practitioners or diabetologists.13, 14 It is therefore not known how best to implement an inpatient diabetes management program that is effective, efficient, and self‐perpetuating. At Brigham and Women's Hospital (BWH), we have been refining a subcutaneous insulin protocol, focused provider education, and more recently a computerized order set to overcome barriers related to fear of hypoglycemia, delays in insulin prescribing, and unfamiliarity with inpatient glucose management.15 The aims of this current trial were to evaluate the effects of these interventions on a geographically localized general medical service previously naive to these interventions to evaluate their effects on glycemic control, patient safety, and processes of care. We hypothesized that these interventions would improve glycemic control and increase use of basal‐bolus insulin orders without increasing the rate of hypoglycemia.

METHODS

Setting and Participants

This prospective, before‐after trial was conducted at BWH from July 15, 2005 through June 22, 2006. Eligible subjects were patients scheduled for admission to the BWH Physician Assistant/Clinician Educator (PACE) Service with either a known diagnosis of type 2 diabetes mellitus or inpatient hyperglycemia (at least 1 random laboratory glucose >180 mg/dL). The PACE service is a geographically‐localized general medicine service of up to 15 beds where patients are cared for by a single cadre of nurses, 2 physician's assistants (PAs), and 1 hospitalist attending. A moonlighter covers the service at night. The PACE service does not accept patients transferred from other acute care hospitals or from ICUs, but does not otherwise have triage guidelines related to diagnosis, complexity, or acuity. Patients were excluded if they had type 1 diabetes, presented with hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA), received total parenteral nutrition (TPN), or were receiving palliative care. This study was approved by the BWH Institutional Review Board; patient consent was deemed not to be necessary for this study given the relatively nonsensitive nature of the data, noninvasive means of data collection, and the steps taken by research personnel to minimize any breach in patient confidentiality.

Intervention

The study intervention consisted of three components, initiated in January 2006:

  • Glycemic management protocol: a multidisciplinary team of a diabetologist (M.L.P.), a hospitalist (J.L.S.), and a pharmacist (Jennifer Trujillo) developed a subcutaneous insulin protocol based on ADA guidelines (Table 1; see the appendix for complete protocol). The protocol was approved by the BWH Pharmacy and Therapeutics Diabetes Subcommittee and refined through 6 months of pilot testing on other general medical services.15 The protocol consisted of a set of specific treatment recommendations, including: (1) bedside glucose monitoring; (2) stopping oral diabetes agents in most patients; (3) estimating total daily insulin requirements; (4) prescribing basal, nutritional, and supplemental insulin based on the patient's total insulin requirements, preadmission medication regimen, and nutritional status; (5) adjusting insulin on a daily basis as needed; (6) managing hypoglycemia; (7) suggestions for discharge orders; and (8) indications for an endocrinology consultation. The protocol was printed as a pocket guide, distributed to all members of the PACE service, and used to guide all other interventions.

  • Diabetes education: all PAs received 2 one‐hour educational sessions: a lecture by a diabetologist (M.L.P.) reviewing the rationale for tight glycemic control and general principles of management, and a workshop by a hospitalist (J.L.S.) in which specific cases were reviewed to illustrate how the protocol could be used in practice (eg, when oral agents could be safely continued, how to prescribe insulin on admission, and how to make subsequent adjustments in dose). All hospitalist attendings received a 1‐hour lecture summarizing the above material. All nurses on the service received a lecture that focused on issues unique to nursing care, such as insulin administration, glucose testing, managing patients with unpredictable oral (PO) intake, and patient education. (All materials are available from the authors upon request).

  • Order Set: an order set, built into BWH's proprietary computer provider order entry (CPOE) system, was created to parallel the glycemic management protocol and facilitate insulin orders for patients eating discrete meals, receiving continuous liquid enteral nutrition (tube feeds), or receiving nothing by mouth (NPO). Other components of the order set facilitated glucose monitoring and other laboratory tests and ordering consultation when appropriate.

 

Summary of Inpatient Diabetes Management Protocol
Oral AgentsStop Oral Agents in Most Patients
  • NOTE: See the Appendix for full description of insulin protocol.

  • Abbreviations: A1C, glycosylated hemoglobin; IM, intramuscular; IV, intravenous; NPO, not eating (nothing by mouth); PO, eating (by mouth); qAM, every morning, qHS, at bedtime.

Glucose testingCheck bedside blood glucose before meals and at bedtime if eating, or every 6 hours if NPO
Insulin 
1. Estimate total daily insulin dose0.5 to 0.7 units/kg/day, depending on patient's age, size, renal function, insulin sensitivity, history of hypoglycemia, and steroid use
2. Start basal insulinPatient's home dose or 50% of calculated total daily dose; NPH qAM/qHS or insulin glargine qHS; If NPO, use one‐half the home dose unless hyperglycemic
3. Start nutritional insulin if not NPOPatient's home dose or 50% of calculated total daily dose, less if poor or unknown intake; discrete meals: insulin aspart split over 3 meals, 0 to 15 minutes prior to eating; continuous tube feeds or IV dextrose: regular insulin every 6 hours
4. Start correctional insulin1 of 3 scales provided based on total daily dose of insulin; same type as nutritional insulin; regular insulin if NPO
5. Daily adjustmentCalculate total administered dose from prior day, adjust for degree of hyperglycemia or hypoglycemia, renal function, PO intake, steroid use, and degree of illness, and redistribute as 50% basal, 50% nutritional, or 100% basal if NPO
Hypoglycemia ordersJuice, IV dextrose, or IM glucagon depending on ability to take oral nutrition and IV access
Discharge ordersBased on A1C: either home regimen, titration of home regimen, or new insulin regimen (if latter, simple regimen with aggressive patient education and prompt follow‐up)
Indications for endocrine consultationLabile blood sugars, poor control, prolonged NPO period, question of type 1 or type 2 diabetes

Study Protocol and Data Collection

A research assistant prospectively identified eligible patients each weekday by screening all patients scheduled for admission to the PACE service using the daily computerized sign‐out system used on all general medical teams. Specifically, laboratory random glucose levels, inpatient medications, and medical histories were reviewed to determine if each patient met eligibility criteria. Eligibility criteria were then confirmed by medical record review and adjudicated by one study author (J.L.S.) if necessary. Further medical record review was performed to identify specific patient populations (eg, diet‐controlled, steroid‐induced, or previously undiagnosed diabetes), determine preadmission diabetes medications, and determine the patient's weight. Hospital computerized clinical and administrative records were abstracted to obtain patient demographics (age, sex, race, insurance status), laboratory data (glucose level on admission, A1C level [taken during or within 6 months prior to admission]), clinical data (length of stay, billing‐based Charlson comorbidity score,16 and diagnosis‐related group [DRG] case mix index), all inpatient insulin and oral diabetes medication orders, frequency of bedside glucose testing, and diet orders. Electronic medication administration record (eMAR) data were used to determine all doses and times of insulin administration.

Outcomes

The primary outcome was the mean percent of glucose readings between 60 and 180 mg/dL per patient (ie, calculated for each patient and averaged across all eligible patients in each study arm). Only bedside glucose readings were used given the lack of additional useful information typically provided by laboratory (venous plasma) glucose readings.17 Readings drawn within 1 hour of a previous reading were excluded to avoid ascertainment bias caused by follow‐up testing of abnormal glucose values. Only readings while on the study service were used. Readings on hospital day 1 were excluded because our intervention was expected to have little impact on the first day's glucose control; for patients with undiagnosed diabetes, data collection began the day following the first elevated glucose reading. Readings beyond hospital day 14 were also excluded to avoid biased data from patients with exceptionally long lengths of stay.

Secondary outcomes included the following:

  • Glycemic control:

     

    • Patient‐day weighted mean glucose (ie, mean glucose for each patient‐day, averaged across all patient days);

    • Mean glucose per patient for each hospital day (days 17).

    • Patient safety:

       

      • Proportion of patient‐days with any glucose reading <60 mg/dL (hypoglycemia) and <40 mg/dL (severe hypoglycemia).

      • Processes of care:

         

        • Use of any NPH insulin or insulin glargine (basal) insulin during the hospitalization if 2 or more glucose readings were >180 mg/dL.

        • Adequacy of basal dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission basal dose or 0.20 to 0.42 units/kg if not known or not taken prior to admission. If not eating, half the above calculations.

        • Use of any scheduled nutritional insulin during the hospitalization if ever prescribed a diet and 2 or more glucose readings were greater than 180 mg/dL.

        • Adequacy of nutritional dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission nutritional dose or 0.20 to 0.42 units/kg/day if not known or not taken prior to admission. Patients on clear liquid diets, enteral feeds, or receiving glucocorticoids were excluded from this analysis.

        • Correct type of nutritional insulin: if eating discrete meals, insulin aspart (the rapid‐acting insulin on formulary at BWH); if prescribed tube feeds, regular insulin.

        • Use of supplemental insulin by itself (without scheduled basal or nutritional insulin), a marker of poor care.

        • A1C testing within 1 month prior to or during hospitalization.

        • Clinical inertia: if at least two glucose readings <60 mg/dL or >180 mg/dL on a patient‐day, lack of any change to any insulin order the following day if still on the study service.

        • Healthcare utilization:

           

          • Hospital length of stay in hours, calculated from the exact time of admission until the exact time of discharge, using hospital administrative data.

           

Analyses

Study results were compared prior to the intervention (July 15 through December 12, 2005) with those during the intervention (January 18 through June 20, 2006). Patient data and clinical outcomes were analyzed descriptively using proportions, means with standard deviations (SDs), or medians with interquartile ranges (IQRs) as appropriate. Comparisons between groups were calculated using Fisher's exact test for dichotomous and categorical variables, and Student t test or Wilcoxon rank sum test for continuous variables as appropriate. The primary outcome was first analyzed using linear regression with study group as the independent variable and percent of glucose readings within range per patient as the dependent variable. We then adjusted for potential confounders by putting each covariate into the model, one at a time. All significant predictors of the outcome at a P value <0.10 were retained in the final model. We used general estimating equations to adjust for clustering of results by each PA. Similar analyses were performed for hospital length of stay per patient using a negative binomial model, so chosen because it fit the data distribution much better than the typically used Poisson model. With a planned sample size of 115 patients and 1250 glucose readings per arm, an intraclass correlation coefficient of 0.10, and an alpha of 0.05, the study had 90% power to detect an increase in percent of glucose readings in range from 67% to 75%. All analyses were based on the intention‐to‐treat principle. Except as above, 2‐sided P values <0.05 were considered significant. SAS version 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

We prospectively identified 248 potential patients for the study. We subsequently excluded 79 patients for the following reasons: no glucose readings beyond hospital day 1 while on PACE service (34 patients); never admitted to PACE service (15 patients); no diabetes or inpatient hyperglycemia (9 patients, mostly patients prescribed an insulin sliding scale prophylactically to avoid steroid‐induced hyperglycemia); type 1 diabetes (13 patients); TPN, DKA, or HHS (5 patients); and palliative care (3 patients). The remaining 169 patients included 63 from the preintervention period(out of 489 total admissions to the PACE service; 13%) and 106 patients in the postintervention period (out of 565 admissions; 19%). These patients had 2447 glucose readings, or an average of 3.6 glucose readings per monitored patient‐day in the preintervention period and 3.3 glucose readings per patient‐day in the postintervention period. Even including the 34 patients who were excluded for lack of glucose readings, glucose data were still available for 717 out of a potential 775 patient‐days (93%). Characteristics for all included patients are shown in Table 2. The mean admission glucose was 197 mg/dL, mean A1C was 8.4%, 54% of the patients were prescribed insulin prior to admission, and 7% had no prior diagnosis of diabetes. There were no significant differences in baseline characteristics between the 2 patient groups except for Charlson score, which was higher in the preintervention group (87% versus 74% with score 2 or higher; Table 2). The top diagnosis‐related groups for the entire cohort included: heart failure and shock (12 patients); kidney and urinary tract infections (12 patients); esophagitis, gastroenteritis, and miscellaneous digestive disorders (11 patients); chronic obstructive pulmonary disease (10 patients); renal failure (10 patients); simple pneumonia and pleurisy (7 patients); disorders of the pancreas except malignancy (6 patients); chest pain (5 patients); and cellulitis (5 patients).

Patient Characteristics
 Preintervention (n = 63)Postintervention (n = 106)P Value
  • Abbreviations: IQR, interquartile range; A1C, glycosylated hemoglobin; SD, standard deviation.

Mean age, year (SD)63.0 (15.7)64.7 (14.3)0.52
Male, n (%)25 (40)52 (49)0.27
Race, n (%)  0.33
White29 (46)42 (40) 
Black21 (33)28 (26) 
Hispanic11 (17)30 (28) 
Unknown2 (3)6 (6) 
Admission glucose, mg/dL (SD)188 (90.9)203 (96.1)0.33
A1C, % (SD)8.5 (2.4)8.3 (2.4)0.85
Insulin use prior to admission, n (%)38 (60)54 (51)0.48
Case mix index, median (IQR)0.89 (0.781.11)0.91 (0.841.22)0.33
Charlson index, n (%)  0.03
018 (13)28 (26) 
2329 (46)27 (26) 
4515 (24)29 (27) 
>511 (17)22 (21) 
Known history of diabetes, n (%)62 (98)96 (91)0.06

With respect to insulin ordering practices, there was no significant difference in the use of basal insulin in hyperglycemic patients between the preintervention period and postintervention period (81% versus 91%; P = 0.17), nor in the dose of basal insulin prescribed (results not shown), but there was an increase in the use of scheduled nutritional insulin for those patients with hyperglycemia receiving nutrition: 40% versus 75%, P < 0.001 (Table 3). The percent of patients receiving supplemental (sliding scale) insulin by itself (ie, without ever receiving basal or nutritional insulin) was lower during the postintervention period (29% versus 8%, P < 0.001). Nonsignificant differences were seen in the rates of prescribing an appropriate dose and type of nutritional insulin. Notably, there was no difference at all in the proportion of patient‐days in which insulin adjustments were made when 2 or more episodes of hyperglycemia or hypoglycemia were present during the previous day (56% of patient‐days in both groups; P = 0.90).

Study Outcomes
 Preintervention (n = 63)Postintervention (n = 106)Unadjusted Effect Size (95% CI)Adjusted Effect Size (95% CI)
  • Abbreviations: A1C, glycosylated hemoglobin; PO, eating (by mouth); SD, standard deviation.

  • Effect size is absolute percent increase in glucose readings in range, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • P < 0.05.

  • Effect size is absolute increase in mean glucose in mg/dL, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • Effect size is odds ratio for having a patient‐day with hypoglycemia, adjusted for most recent A1C and insulin use prior to admission.

  • Effect size is relative increase in length of stay, adjusted for patient insurance, race, gender, and Charlson comorbidity score.

  • Effect size is odds ratio for achieving each process measure. No multivariable adjustment was performed for process measures.

  • Excluding patients receiving a clear liquid diet, receiving enteral feeding, or receiving systemic glucocorticoid treatment.

Mean percent glucose readings 60180 mg/dL per patient (SD)59.1 (0.28)64.7 (0.27)+5.6 (3.0 to +14.3)+9.7 (+0.6 to +18.8)*,
Patient‐day weighted mean glucose, mg/dL (SD)174.7 (60.0)164.6 (54.2)10.1 (1.6 to 18.5)15.6 (6.4 to 24.9),
Percent patient‐days with any glucose <60 mg/dL16/293 (5.5%)26/424 (6.1%)1.1 (0.6 to 2.1)1.1 (0.6 to 2.1)
Percent patient‐days with any glucose <40 mg/dL3/293 (1.0%)5/424 (1.2%)1.3 (0.3 to 5.9)1.1 (0.3 to 5.1)
Hospital length of stay, hours, mean (SD)112.2 (63.3)86.0 (89.6)30% (5% to 51%)25% (6% to 44%),
Basal insulin if inpatient hyperglycemia (2 or more readings >180 mg/dL)39/48 (81%)67/74 (91%)2.2 (0.8 to 6.4) 
Nutritional insulin if inpatient hyperglycemia and PO intake19/48 (40%)53/71 (75%)4.5 (2.0 to 9.9), 
Adequate initial dose of nutritional insulin (home dose or 0.200.42 units/kg/day)#2/9 (22%)22/49 (45%)2.9 (0.5 to 15.1) 
Supplemental insulin alone (without basal or nutritional insulin)16/56 (29%)7/92 (8%)0.2 (0.08 to 0.5), 
Insulin changed if previous day's glucose out of range (2 or more values <60 or >180 mg/dL)70/126 (56%)76/135 (56%)1.0 (0.6 to 1.6) 
A1C tested during hospitalization if not available within 30 days prior38/63 (60%)74/106 (70%)1.5 (0.8 to 2.9) 

The primary outcome, the mean percent of glucose readings between 60 and 180 mg/dL per patient, was 59.1% in the preintervention period and 64.7% in the postintervention (P = 0.13 in unadjusted analysis; Table 3). When adjusted for A1C, admission glucose, and insulin use prior to admission, the adjusted absolute difference in the percent of glucose readings within range was 9.7% (95% confidence interval [CI], 0.6%‐18.8%; P = 0.04; Table 3). Regarding other measures of glucose control, the patient‐day weighted mean glucose was 174.7 mg/dL in the preintervention period and 164.6 mg/dL postintervention (P = 0.02), and there was no significant difference in the percent of patient‐days with any hypoglycemia (glucose <60 mg/dL) or severe hypoglycemia (glucose <40 mg/dL; Table 3). There were also no significant differences in the mean number of hypoglycemic events per patient‐day (6.8 versus 6.6 per 100 patient‐days; relative risk, 0.95; 95% CI, 0.541.67; P = 0.87) or severe hypoglycemic events per patient‐day (1.0 versus 1.4 per 100 patient‐days; relative risk, 1.38; 95% CI, 0.355.53; P = 0.65).

We also compared hospital length of stay in hours between the study groups (Table 3). Length of stay (LOS) was shorter in the postintervention arm in unadjusted analyses (112 versus 86 hours; P < 0.001), and this difference persisted when adjusted for patient insurance, race, gender, and Charlson comorbidity score (25% shorter; 95% CI, 6%‐44%). A comparison of LOS among nonstudy patients on the PACE service during these 2 time periods revealed no difference (105 versus 101 hours). When the length of stay analysis was limited to study patients with a known diagnosis of diabetes, the adjusted effect size was a 31% relative decrease in length of stay.

Figure 1A shows the percent glucose readings within range per patient by hospital day. The greatest differences between groups can be seen on hospital days 2 and 3 (11% absolute differences on both days). Similarly, Figure 1B shows the mean glucose per patient by hospital day. Again, the biggest differences are seen on hospital days 2 and 3 (20 and 23 mg/dL difference between groups, respectively). In both cases, only the day 3 comparisons were significantly different between study groups.

Figure 1
Diagnostic and treatment algorithm for sleep in hospitalized medical patients.

DISCUSSION

In this before‐after study, we found that a multifaceted intervention consisting of a subcutaneous insulin protocol, focused education, and an order set built into the hospital's CPOE system was associated with a significantly higher percentage of glucose readings within range per patient in analyses adjusted for patient demographics and severity of diabetes. We also found a significant decrease in patient‐day weighted mean glucose, a marked increase in appropriate use of scheduled nutritional insulin, and a concomitant decrease in sliding scale insulin only regimens during the postintervention period. Moreover, we found a shorter length of stay during the postintervention period that persisted after adjustment for several clinical factors. Importantly, the interventions described in this study require very few resources to continue indefinitely: printing costs for the management protocol, 4 hours of education delivered per year, and routine upkeep of an electronic order set.

Because this was a before‐after study, we cannot exclude the possibility that these improvements in process and outcome were due to cointerventions and/or temporal trends. However, we know of no other interventions aimed at improving diabetes care in this self‐contained service of nurses, PAs, and hospitalists. Moreover, the process improvements, especially the increase in scheduled nutritional insulin, were rather marked, unlikely to be due to temporal trends alone, and likely capable of producing the corresponding improvements in glucose control. That glucose control stopped improving after hospital day 3 may be due to the fact that subsequent adjustment to insulin orders occurred infrequently and no more often than prior to the intervention. That we did not see greater improvements in glycemic control overall may also reflect the fact that 81% of study patients with inpatient hyperglycemia received basal insulin prior to the intervention.

The reduction in patient LOS was somewhat surprising given the relatively small sample size. However, the results are consistent with those of other studies linking hyperglycemia to LOS18, 19 and we found no evidence for a temporal trend toward lower LOS on the PACE service as a whole during the same time period. While a greater proportion of patients on the PACE service were in the study in the post‐intervention period compared with the preintervention period, we found no evidence that the difference in length of stay was due to increased surveillance for nondiabetics, especially because eligibility criteria depended on phlebotomy glucose values, which were uniformly tested in all inpatients. Also, effects on length of stay were actually stronger when limited to patients with known diabetes. Finally, we controlled for several predictors of length of stay, although we still cannot exclude the possibility of unmeasured confounding between groups.

Since ADA and ACE issued guidelines for inpatient management of diabetes and hyperglycemia, many institutions have developed subcutaneous insulin algorithms, educational curricula, and/or order sets to increase compliance with these guidelines and improve glycemic control. Some of these efforts have been studied and some have been successful in their efforts.13, 14, 2023 Unfortunately, most of these programs have not rigorously assessed their impact on process and outcomes, and the most effective studies published to date have involved interventions much more intensive than those described here. For example, Rush University's intervention was associated with a 50 mg/dL decrease in mean blood glucose but involved an endocrinologist rounding twice daily with house officers for 2 weeks at a time.13 At Northwestern University, a diabetes management service run by nurse practitioners was established, and the focus was on the conversion from intravenous to subcutaneous insulin regimens.14 The RABBIT 2 study that demonstrated the benefits of a basal‐bolus insulin regimen used daily rounding with an endocrinologist.12 More modestly, a program in Pitt County Memorial Hospital in Greenville, NC, relied mostly on diabetes nurse case managers, a strategy which reduced hospital‐wide mean glucose levels as well as LOS, although the greatest improvements in glycemic control were seen in the ICU.19 Our findings are much more consistent with those from University of California San Diego, as yet unpublished, which also used an algorithm, computerized order set, education, as well as continuous quality improvement methods to achieve its aims.22

Our study has several limitations, including being conducted on 1 general medicine service at 1 academic medical center. Moreover, this service, using a physician assistant/hospitalist model, a closed geographic unit, and fairly generous staffing ratio, is likely different from those in many settings and may limit the generalizability of our findings. However, this model allowed us to conduct the study in a laboratory relatively untouched by other cointerventions. Furthermore, the use of PAs in this way may become more common as both academic and community hospitals rely more on mid‐level providers. Our study had a relatively low percentage of patients without a known diagnosis of diabetes compared with other studies, again potentially but not necessarily limiting generalizability. This finding has been shown in other studies at our institution24 and may be due to the high rate of screening for diabetes in the community. Another limitation is that this was a nonrandomized, before‐after trial. However, all subjects were prospectively enrolled to improve comparability, and we performed rigorous adjustment for multiple potential confounding factors. Also, this study had limited statistical power to detect differences in hypoglycemia rates. The preintervention arm was smaller than planned due to fewer diabetic patients than expected on the service and a higher number of exclusions; we prolonged the postintervention period to achieve the desired sample size for that arm of the study.

Our study also has several strengths, including electronic capture of many processes of care and a methodology to operationalize them into measures of protocol adherence. Our metrics of glycemic control were rigorously designed and based on a national task force on inpatient glycemic control sponsored by the Society of Hospital Medicine, with representation from the ADA and AACE.25

Potential future improvements to this intervention include modifications to the daily adjustment algorithm to improve its usability and ability to improve glucose control. Another is the use of high‐reliability methods to improve order set use and daily insulin adjustment, including alerts within the CPOE system and nurse empowerment to contact medical teams if glucose levels are out of range (eg, if greater than 180 mg/dL, not just if greater than 350 or 400 mg/dL). Future research directions include multicenter, randomized controlled trials of these types of interventions and an analysis of more distal patient outcomes including total healthcare utilization, infection rates, end‐organ damage, and mortality.

In conclusion, we found a relationship between a relatively low‐cost quality improvement intervention and improved glycemic control in the non‐ICU general medical setting. Such a finding suggests the benefits of the algorithm itself to improve glucose control and of our implementation strategy. Other institutions may find this intervention a useful starting point for their own quality improvement efforts. Both the algorithm and implementation strategy are deserving of further improvements and future study.

Acknowledgements

We thank Paul Szumita, Karen Fiumara, Jennifer Trujillo, and the other members of the BWH Diabetes Pharmacy and Therapeutics Subcommittee for their help designing and implementing the intervention; Aubre McClendon, Nicole Auclair, Emily Dattwyler, Mariya Fiman, and Alison Pietras for valuable research assistance; Deborah Williams for data analysis; Amy Bloom for project support; and Stuart Lipsitz for biostatistical expertise.

APPENDIX

INPATIENT DIABETES MANAGEMENT PROTOCOL

Management of Diabetes and Hyperglycemia in Hospitalized Non‐ICU Patients

Rationale

Increasing data show a strong association between hyperglycemia and adverse inpatient outcomes. The American Diabetes Association and the American College of Clinical Endocrinology recommend all glucose levels be below 180 mg/dL in non‐ICU patients. Because hospitalizations are unstable situations, even patients who are well controlled on oral agents as outpatients are usually best managed with insulin.

Insulin may be safely administered even to patients without previously diagnosed diabetes. As long as the prescribed doses are below what is normally produced by the pancreas, the patient will not become hypoglycemic. If the glucose level drops, endogenous insulin secretion will reduce to compensate.

Total insulin requirements in insulin‐sensitive patients (eg, type 1 diabetes mellitus) is 0.50.7/units/kg/day. Insulin requirements in insulin‐resistant type 2 diabetic patients may vary greatly, and can exceed 12 units/kg/day. A conservative estimate for initial insulin therapy in any patient with diabetes is to start with the type 1 diabetes mellitus dose, 0.50.7 units/kg/day.

Overview

Effective inpatient insulin regimens typically include 3 components:

  • Basal insulin (eg, scheduled NPH or insulin glargine [Lantus]), which is used to manage fasting and premeal hyperglycemia.

  • Nutritional or prandial insulin (eg, scheduled regular insulin, insulin lispro [Humalog] or insulin aspart [Novolog]) which controls hyperglycemia from nutritional (eg, discrete meals, TPN, IV dextrose) sources.

  • Supplemental or correctional insulin (eg, regular insulin, insulin lispro, or insulin aspart), which is used in addition to scheduled insulin to meet unexpected basal hyperglycemia that is not covered by the scheduled insulin.

 

Sample Orders (Not for Patients with Uncontrolled Type 1 Diabetes, DKA, Hyperglycemic Hyperosmolar State, or Other Absolute Need for IV Insulin)

 

  • Check (fingerstick) capillary blood glucose qAC, qHS.

  • NPH insulin subcutaneously (SC) ___ units qAM, ___ units qHS.

  • Insulin aspart SC ___ units pre‐breakfast, ___ units pre‐lunch, ___ units pre‐dinner, hold if NPO or premeal BS <60 mg/dL; give 015 minutes before meals.

  • Insulin aspart SC sliding scale (see Table 6) qAC, in addition to standing nutritional insulin, 015 minutes before meals.

  • For BS <60 mg/dL:

     

    • If patient can take PO

       

      • Give 15 g of fast acting carbohydrate (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets).

      • Repeat finger capillary glucose every 15 (q15) minutes and repeat above (5.a.i.) if BG <60 mg/dL.

      • When BG >60 mg/dL, give snack or meal in a half‐hour.

      • If patient cannot take PO

         

        • Give 25 mL of 50% dextrose (D50) as an IV push.;

        • Repeat finger capillary glucose q15 minutes and repeat above (5.b.i.) if BG <80 mg/dL.

         

Guidelines

 

  • Stop oral diabetes agents in most patients (see Table 7 for list of contraindications and precautions).

  • Check bedside blood glucose (BBG or fingerstick) qAC and qHS (or at 0600 hours, 1200 hours, 1800 hours, and 2400 hours if no discrete meals).

  • Estimate total daily insulin requirement:

     

    • For most patients, conservative estimate is 0.50.7 units/kg/day, but may be much higher.

    • Reasons for lower end of the range: renal insufficiency, small size, insulin sensitive (eg, type 1), recent hypoglycemia, decreasing doses of steroids, older age.

    • Reasons for higher end of the range: obese, initiation or increasing doses of steroids, marked hyperglycemia.

    • Start basal insulin if any premeal BG >140 mg/dL and no recent glucose <60 mg/dL off insulin (Table 5).

    • Start nutritional or prandial insulinhold if nutrition is stopped/held or premeal BS <60 (Table 5).

    • Start supplemental/correctional insulin in addition to nutritional (prandial) insulin (Table 6):

       

      • Discrete meals: Insulin aspart qAC (with nutritional insulin). 0

      • No discrete meals: Regular insulin q6h.

      • On a daily basis, adjust scheduled insulin based on previous days' blood sugars:

         

        • Add up total insulin given the previous day, including scheduled and supplemental insulin, to determine new total daily insulin requirement.

        • Adjust total daily insulin requirement based on clinical considerations (eg, give more if marked hyperglycemia, eating more, improving renal function, increasing steroids; give less if eating less, worsening renal function, tapering steroids, recovering from severe illness).

        • Give 50% of requirement as basal and 50% as nutritional, as above (may need proportionately less nutritional insulin if appetite poor or unknown).

        • Adjust sliding scale if needed based on total scheduled insulin dose (see step 6, above).

        • For BG <60 mg/dL:

           

          • If patient can take PO, give 15 g of fast acting carbohydrate.

          • (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets; not juice plus sugar).

          • Repeat finger capillary glucose q15 minutes and repeat above if BG <60.

          • When BG >60, give snack or meal in half an hour.

          • If patient cannot take PO, give 25 mL of D50 as IV push.

          • Check finger capillary glucose q15 minutes and repeat above if BG <80.

          • Discharge orders:

             

            • Patient should be discharged home on a medication regimen that was similar to the admission regimen (ie, the regimen prescribed by their PCP). Exceptions include

               

              • The patient has a contraindication to an admission medication.

              • There is evidence of severe hyperglycemia (eg, very high A1C) or hypoglycemia on admission regimen.

              • If a patient is admitted with no insulin, and requires insulin to be continued as an outpatient (eg, newly‐diagnosed type 1 diabetes, A1C very high, and contraindication to or on maximum oral regimen), limit discharge insulin regimen to no more than 1 injection per day (eg, hs NPH; an exception to this is for type 1 diabetic patients, who are optimally treated with 34 injections/day). Make sure the patient has prompt follow‐up with their primary care provider (PCP).

              • Avoid discharging home on sliding scale.

              • If a patient is going to require insulin injections and self‐monitoring blood glucose as an outpatient, make sure they are instructed about how to perform these.

              • Indications for calling an endocrine consult:

                 

                • Labile blood sugars.

                • Prolonged periods of NPO, eg, for procedures, especially in patients with type 1 diabetes

                • Marked hyperglycemia despite following this guideline.

                • Question of type 1 versus type 2 versus other type of diabetes. 0

                 

                Basil Insulin Guidelines
                Home Insulin RegimenStarting Dose of Basal InsulinConsiderations
                • NOTE: Patients with T1DM require basal insulin at all times! Basal never should be held!

                • Abbreviations: NPO, nothing by mouth.

                On basal (eg, NPH or glargine) insulin at homePatient's home dose of NPH or glargineIf NPO, consider starting half of NPH or glargine home dose, unless hyperglycemic at home.
                Not on basal (eg, NPH or glargine) insulin at homeNPH 50% of total daily insulin requirement, given qHS or split qAM/qHS (maximum starting dose 20 units/day)Same dose if patient has previously diagnosed or undiagnosed diabetes
                Nutritional Insulin Guidelines
                Type of NutritionCommon Nutritional RegimensSample Starting Doses
                • Abbreviation: qAM, every morning; qHS, at bed time.

                • If receiving cycled tube feeds at night, give nutritional NPH qHS only.

                Discrete mealsAspart given 015 minutes before mealsHome dose, if known or
                50% of total insulin requirement, split over 3 meals, may need less if poor or unknown appetite
                Continuous tube feeding,* IV dextroseNPH qHS or qAM/qHS50% of total insulin requirement (in addition to basal dose), may need less if not at goal caloric intake
                Glargine given every day (qd), anytime
                Regular every 6 hours (q6h)
                Sample Supplemental/Correctional Insulin Scales
                Blood GlucoseScheduled Insulin < 40 Units/DayScheduled Insulin of 4080 Units/DayScheduled Insulin > 80 Units/DayIndividualized
                • NOTE: Avoid supplemental insulin qHS unless patient is very hyperglycemic and obese.

                1501991 unit1 unit2 units____ units
                2002492 units3 units4 units____ units
                2502993 units5 units7 units____ units
                3003494 units7 units10 units____ units
                >3495 units + call HO8 units + call HO12 units + call HO___ units + call HO
                Notes on Oral Agents
                AgentsConsiderationsMetabolism
                Sulfonylureas/secretagogues: glyburide, glipizide, glimeperide (Amaryl); repaglinide (Prandin); nateglinide (Starlix)Risk for hypoglycemiaMetabolized in liver; Glyburide metabolized to active metabolites; 50% renally eliminated
                MetforminContraindicated in heart failure and renal dysfunction (creatinine [Cr] >1.5 mg/dL in men and 1.4 mg/dL in women)Eliminated renally
                Should be held at time of iodinated contrast studies. (May be restarted after normal postcontrast renal function is confirmed)
                Adverse effects include diarrhea, nausea, and anorexia
                Thiazolidinediones: pioglitazone (Actos), rosiglitazone (Avandia)Contraindicated in class III and IV heart failureMetabolized in liver
                Use with caution in patients with edema
                Adverse effects include increased intravascular volume
                Slow onset of action
                Avoid in hepatic dysfunction
                Glucosidease inhibitors: acarbose (Precose), miglitol (Glycet)Gastrointestinal intoleranceAcarbose eliminated in gut and renally
References
  1. Wexler DJ,Meigs JB,Cagliero E,Nathan DM,Grant RW.Prevalence of hyper‐ and hypoglycemia among inpatients with diabetes: a national survey of 44 U.S. hospitals.Diabetes Care.2007;30:367369.
  2. Umpierrez GE,Isaacs SD,Bazargan N,You X,Thaler LM,Kitabchi AE.Hyperglycemia: an independent marker of in‐hospital mortality in patients with undiagnosed diabetes.J Clin Endocrinol Metab.2002;87:978982.
  3. Baker EH,Janaway CH,Philips BJ, et al.Hyperglycaemia is associated with poor outcomes in patients admitted to hospital with acute exacerbations of chronic obstructive pulmonary disease.Thorax.2006;61:284289.
  4. Capes SE,Hunt D,Malmberg K,Pathak P,Gerstein HC.Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview.Stroke.2001;32:24262432.
  5. Cheung NW,Napier B,Zaccaria C,Fletcher JP.Hyperglycemia is associated with adverse outcomes in patients receiving total parenteral nutrition.Diabetes Care.2005;28:23672371.
  6. Clement S,Braithwaite SS,Magee MF, et al.Management of diabetes and hyperglycemia in hospitals.Diabetes Care.2004;27:553597.
  7. McAlister FA,Majumdar SR,Blitz S,Rowe BH,Romney J,Marrie TJ.The relation between hyperglycemia and outcomes in 2471 patients admitted to the hospital with community‐acquired pneumonia.Diabetes Care.2005;28:810815.
  8. Van den Berghe G,Wilmer A,Hermans G, et al.Intensive insulin therapy in the medical ICU.N Engl J Med.2006;354:449461.
  9. van den Berghe G,Wouters P,Weekers F, et al.Intensive insulin therapy in the critically ill patients.N Engl J Med.2001;345:13591367.
  10. Standards of medical care in diabetes, 2007.Diabetes Care.2007;30(Suppl 1):S4S41.
  11. American College of Endocrinology and American Diabetes Association Consensus statement on inpatient diabetes and glycemic control: a call to action.Diabetes Care.2006;29:19551962.
  12. Umpierrez GE,Smiley D,Zisman A, et al.Randomized study of basal‐bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial).Diabetes Care.2007;30:21812186.
  13. Baldwin D,Villanueva G,McNutt R,Bhatnagar S.Eliminating inpatient sliding‐scale insulin: a reeducation project with medical house staff.Diabetes Care.2005;28:10081011.
  14. DeSantis AJ,Schmeltz LR,Schmidt K, et al.Inpatient management of hyperglycemia: the Northwestern experience.Endocr Pract.2006;12:491505.
  15. Trujillo JM,Barsky EE,Greenwood BC, et al.Improving glycemic control in medical inpatients: a pilot study.J Hosp Med.2008;3:5563.
  16. Deyo RA,Cherkin DC,Ciol MA.Adapting a clinical comorbidity index for use with ICD‐9‐CM administrative databases.J Clin Epidemiol.1992;45:613619.
  17. Goldberg PA,Bozzo JE,Thomas PG, et al.“Glucometrics”—assessing the quality of inpatient glucose management.Diabetes Technol Ther.2006;8:560569.
  18. Garg R,Bhutani H,Alyea E,Pendergrass M.Hyperglycemia and length of stay in patients hospitalized for bone marrow transplantation.Diabetes Care.2007;30:993994.
  19. Newton CA,Young S.Financial implications of glycemic control: results of an inpatient diabetes management program.Endocr Pract.2006;12(Suppl 3):4348.
  20. Elinav H,Wolf Z,Szalat A, et al.In‐hospital treatment of hyperglycemia: effects of intensified subcutaneous insulin treatment.Curr Med Res Opin.2007;23:757765.
  21. Levetan CS,Salas JR,Wilets IF,Zumoff B.Impact of endocrine and diabetes team consultation on hospital length of stay for patients with diabetes.Am J Med.1995;99:2228.
  22. Maynard GA,Lee J,Fink E,Renvall M.Effect of a standardized insulin order set and an insulin management algorithm on inpatient glycemic control and hypoglycemia. Society of Hospital Medicine Annual Meeting, 2007; Dallas, TX;2007.
  23. Sampson MJ,Crowle T,Dhatariya K, et al.Trends in bed occupancy for inpatients with diabetes before and after the introduction of a diabetes inpatient specialist nurse service.Diabet Med.2006;23:10081015.
  24. Schnipper JL,Barsky EE,Shaykevich S,Fitzmaurice G,Pendergrass ML.Inpatient management of diabetes and hyperglycemia among general medicine patients at a large teaching hospital.J Hosp Med.2006;1:145150.
  25. Maynard GA,Wesorick DH,Magee MF, et al. Improving glycemic control, preventing hypoglycemia, and optimizing care of the inpatient with hyperglycemia and diabetes, 2006. Available at:http://www.hospitalmedicine.org/ResourceRoomRedesign/html/GC_Imp_Guide.cfm. Accessed October 2008.
Article PDF
Issue
Journal of Hospital Medicine - 4(1)
Publications
Page Number
16-27
Legacy Keywords
clinical protocols, clinical trial, diabetes mellitus, hyperglycemia, inpatients, insulin, outcome measurement (healthcare), quality of healthcare
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Article PDF
Article PDF

Diabetes mellitus and/or inpatient hyperglycemia are common comorbid conditions in hospitalized patients. Recent surveys show that over 90% of hospitalized diabetic patients experience hyperglycemia (>200 mg/dL), and in nearly 1 in 5 of these patients hyperglycemia persists for 3 days or more.1 Hyperglycemia among inpatients without a previous history of diabetes mellitus is also very common.2 Observational studies have shown that hyperglycemia in hospitalized patients is associated with adverse outcomes including infectious complications, increased length of stay, and increased mortality.27 Recent randomized controlled trials have demonstrated that aggressive treatment of inpatient hyperglycemia improves outcomes in surgical and medical intensive care units.8, 9

Based on the available data, the American Diabetes Association (ADA) now advocates good metabolic control, defined as preprandial glucose levels of 90 to 130 mg/dL and peak postprandial glucose levels <180 mg/dL in hospitalized nonintensive care unit (ICU) patients.10 To reach these targets, the ADA and American College of Endocrinology (ACE) suggest that multidisciplinary teams develop and implement hyperglycemia management guidelines and protocols.11 Protocols should promote the use of continuous intravenous insulin infusions or scheduled basal‐bolus subcutaneous insulin regimens. Subcutaneous insulin protocols should include target glucose levels, basal, nutritional, and supplemental insulin, and daily dose adjustments.6 A recent randomized controlled trial of non‐ICU inpatients demonstrated that such a basal‐bolus insulin regimen results in improved glucose control compared with a sliding scale only regimen.12

To date, few published studies have investigated the best ways to implement such management protocols; those that have are often resource‐intensive, for example involving daily involvement of nurse practitioners or diabetologists.13, 14 It is therefore not known how best to implement an inpatient diabetes management program that is effective, efficient, and self‐perpetuating. At Brigham and Women's Hospital (BWH), we have been refining a subcutaneous insulin protocol, focused provider education, and more recently a computerized order set to overcome barriers related to fear of hypoglycemia, delays in insulin prescribing, and unfamiliarity with inpatient glucose management.15 The aims of this current trial were to evaluate the effects of these interventions on a geographically localized general medical service previously naive to these interventions to evaluate their effects on glycemic control, patient safety, and processes of care. We hypothesized that these interventions would improve glycemic control and increase use of basal‐bolus insulin orders without increasing the rate of hypoglycemia.

METHODS

Setting and Participants

This prospective, before‐after trial was conducted at BWH from July 15, 2005 through June 22, 2006. Eligible subjects were patients scheduled for admission to the BWH Physician Assistant/Clinician Educator (PACE) Service with either a known diagnosis of type 2 diabetes mellitus or inpatient hyperglycemia (at least 1 random laboratory glucose >180 mg/dL). The PACE service is a geographically‐localized general medicine service of up to 15 beds where patients are cared for by a single cadre of nurses, 2 physician's assistants (PAs), and 1 hospitalist attending. A moonlighter covers the service at night. The PACE service does not accept patients transferred from other acute care hospitals or from ICUs, but does not otherwise have triage guidelines related to diagnosis, complexity, or acuity. Patients were excluded if they had type 1 diabetes, presented with hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA), received total parenteral nutrition (TPN), or were receiving palliative care. This study was approved by the BWH Institutional Review Board; patient consent was deemed not to be necessary for this study given the relatively nonsensitive nature of the data, noninvasive means of data collection, and the steps taken by research personnel to minimize any breach in patient confidentiality.

Intervention

The study intervention consisted of three components, initiated in January 2006:

  • Glycemic management protocol: a multidisciplinary team of a diabetologist (M.L.P.), a hospitalist (J.L.S.), and a pharmacist (Jennifer Trujillo) developed a subcutaneous insulin protocol based on ADA guidelines (Table 1; see the appendix for complete protocol). The protocol was approved by the BWH Pharmacy and Therapeutics Diabetes Subcommittee and refined through 6 months of pilot testing on other general medical services.15 The protocol consisted of a set of specific treatment recommendations, including: (1) bedside glucose monitoring; (2) stopping oral diabetes agents in most patients; (3) estimating total daily insulin requirements; (4) prescribing basal, nutritional, and supplemental insulin based on the patient's total insulin requirements, preadmission medication regimen, and nutritional status; (5) adjusting insulin on a daily basis as needed; (6) managing hypoglycemia; (7) suggestions for discharge orders; and (8) indications for an endocrinology consultation. The protocol was printed as a pocket guide, distributed to all members of the PACE service, and used to guide all other interventions.

  • Diabetes education: all PAs received 2 one‐hour educational sessions: a lecture by a diabetologist (M.L.P.) reviewing the rationale for tight glycemic control and general principles of management, and a workshop by a hospitalist (J.L.S.) in which specific cases were reviewed to illustrate how the protocol could be used in practice (eg, when oral agents could be safely continued, how to prescribe insulin on admission, and how to make subsequent adjustments in dose). All hospitalist attendings received a 1‐hour lecture summarizing the above material. All nurses on the service received a lecture that focused on issues unique to nursing care, such as insulin administration, glucose testing, managing patients with unpredictable oral (PO) intake, and patient education. (All materials are available from the authors upon request).

  • Order Set: an order set, built into BWH's proprietary computer provider order entry (CPOE) system, was created to parallel the glycemic management protocol and facilitate insulin orders for patients eating discrete meals, receiving continuous liquid enteral nutrition (tube feeds), or receiving nothing by mouth (NPO). Other components of the order set facilitated glucose monitoring and other laboratory tests and ordering consultation when appropriate.

 

Summary of Inpatient Diabetes Management Protocol
Oral AgentsStop Oral Agents in Most Patients
  • NOTE: See the Appendix for full description of insulin protocol.

  • Abbreviations: A1C, glycosylated hemoglobin; IM, intramuscular; IV, intravenous; NPO, not eating (nothing by mouth); PO, eating (by mouth); qAM, every morning, qHS, at bedtime.

Glucose testingCheck bedside blood glucose before meals and at bedtime if eating, or every 6 hours if NPO
Insulin 
1. Estimate total daily insulin dose0.5 to 0.7 units/kg/day, depending on patient's age, size, renal function, insulin sensitivity, history of hypoglycemia, and steroid use
2. Start basal insulinPatient's home dose or 50% of calculated total daily dose; NPH qAM/qHS or insulin glargine qHS; If NPO, use one‐half the home dose unless hyperglycemic
3. Start nutritional insulin if not NPOPatient's home dose or 50% of calculated total daily dose, less if poor or unknown intake; discrete meals: insulin aspart split over 3 meals, 0 to 15 minutes prior to eating; continuous tube feeds or IV dextrose: regular insulin every 6 hours
4. Start correctional insulin1 of 3 scales provided based on total daily dose of insulin; same type as nutritional insulin; regular insulin if NPO
5. Daily adjustmentCalculate total administered dose from prior day, adjust for degree of hyperglycemia or hypoglycemia, renal function, PO intake, steroid use, and degree of illness, and redistribute as 50% basal, 50% nutritional, or 100% basal if NPO
Hypoglycemia ordersJuice, IV dextrose, or IM glucagon depending on ability to take oral nutrition and IV access
Discharge ordersBased on A1C: either home regimen, titration of home regimen, or new insulin regimen (if latter, simple regimen with aggressive patient education and prompt follow‐up)
Indications for endocrine consultationLabile blood sugars, poor control, prolonged NPO period, question of type 1 or type 2 diabetes

Study Protocol and Data Collection

A research assistant prospectively identified eligible patients each weekday by screening all patients scheduled for admission to the PACE service using the daily computerized sign‐out system used on all general medical teams. Specifically, laboratory random glucose levels, inpatient medications, and medical histories were reviewed to determine if each patient met eligibility criteria. Eligibility criteria were then confirmed by medical record review and adjudicated by one study author (J.L.S.) if necessary. Further medical record review was performed to identify specific patient populations (eg, diet‐controlled, steroid‐induced, or previously undiagnosed diabetes), determine preadmission diabetes medications, and determine the patient's weight. Hospital computerized clinical and administrative records were abstracted to obtain patient demographics (age, sex, race, insurance status), laboratory data (glucose level on admission, A1C level [taken during or within 6 months prior to admission]), clinical data (length of stay, billing‐based Charlson comorbidity score,16 and diagnosis‐related group [DRG] case mix index), all inpatient insulin and oral diabetes medication orders, frequency of bedside glucose testing, and diet orders. Electronic medication administration record (eMAR) data were used to determine all doses and times of insulin administration.

Outcomes

The primary outcome was the mean percent of glucose readings between 60 and 180 mg/dL per patient (ie, calculated for each patient and averaged across all eligible patients in each study arm). Only bedside glucose readings were used given the lack of additional useful information typically provided by laboratory (venous plasma) glucose readings.17 Readings drawn within 1 hour of a previous reading were excluded to avoid ascertainment bias caused by follow‐up testing of abnormal glucose values. Only readings while on the study service were used. Readings on hospital day 1 were excluded because our intervention was expected to have little impact on the first day's glucose control; for patients with undiagnosed diabetes, data collection began the day following the first elevated glucose reading. Readings beyond hospital day 14 were also excluded to avoid biased data from patients with exceptionally long lengths of stay.

Secondary outcomes included the following:

  • Glycemic control:

     

    • Patient‐day weighted mean glucose (ie, mean glucose for each patient‐day, averaged across all patient days);

    • Mean glucose per patient for each hospital day (days 17).

    • Patient safety:

       

      • Proportion of patient‐days with any glucose reading <60 mg/dL (hypoglycemia) and <40 mg/dL (severe hypoglycemia).

      • Processes of care:

         

        • Use of any NPH insulin or insulin glargine (basal) insulin during the hospitalization if 2 or more glucose readings were >180 mg/dL.

        • Adequacy of basal dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission basal dose or 0.20 to 0.42 units/kg if not known or not taken prior to admission. If not eating, half the above calculations.

        • Use of any scheduled nutritional insulin during the hospitalization if ever prescribed a diet and 2 or more glucose readings were greater than 180 mg/dL.

        • Adequacy of nutritional dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission nutritional dose or 0.20 to 0.42 units/kg/day if not known or not taken prior to admission. Patients on clear liquid diets, enteral feeds, or receiving glucocorticoids were excluded from this analysis.

        • Correct type of nutritional insulin: if eating discrete meals, insulin aspart (the rapid‐acting insulin on formulary at BWH); if prescribed tube feeds, regular insulin.

        • Use of supplemental insulin by itself (without scheduled basal or nutritional insulin), a marker of poor care.

        • A1C testing within 1 month prior to or during hospitalization.

        • Clinical inertia: if at least two glucose readings <60 mg/dL or >180 mg/dL on a patient‐day, lack of any change to any insulin order the following day if still on the study service.

        • Healthcare utilization:

           

          • Hospital length of stay in hours, calculated from the exact time of admission until the exact time of discharge, using hospital administrative data.

           

Analyses

Study results were compared prior to the intervention (July 15 through December 12, 2005) with those during the intervention (January 18 through June 20, 2006). Patient data and clinical outcomes were analyzed descriptively using proportions, means with standard deviations (SDs), or medians with interquartile ranges (IQRs) as appropriate. Comparisons between groups were calculated using Fisher's exact test for dichotomous and categorical variables, and Student t test or Wilcoxon rank sum test for continuous variables as appropriate. The primary outcome was first analyzed using linear regression with study group as the independent variable and percent of glucose readings within range per patient as the dependent variable. We then adjusted for potential confounders by putting each covariate into the model, one at a time. All significant predictors of the outcome at a P value <0.10 were retained in the final model. We used general estimating equations to adjust for clustering of results by each PA. Similar analyses were performed for hospital length of stay per patient using a negative binomial model, so chosen because it fit the data distribution much better than the typically used Poisson model. With a planned sample size of 115 patients and 1250 glucose readings per arm, an intraclass correlation coefficient of 0.10, and an alpha of 0.05, the study had 90% power to detect an increase in percent of glucose readings in range from 67% to 75%. All analyses were based on the intention‐to‐treat principle. Except as above, 2‐sided P values <0.05 were considered significant. SAS version 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

We prospectively identified 248 potential patients for the study. We subsequently excluded 79 patients for the following reasons: no glucose readings beyond hospital day 1 while on PACE service (34 patients); never admitted to PACE service (15 patients); no diabetes or inpatient hyperglycemia (9 patients, mostly patients prescribed an insulin sliding scale prophylactically to avoid steroid‐induced hyperglycemia); type 1 diabetes (13 patients); TPN, DKA, or HHS (5 patients); and palliative care (3 patients). The remaining 169 patients included 63 from the preintervention period(out of 489 total admissions to the PACE service; 13%) and 106 patients in the postintervention period (out of 565 admissions; 19%). These patients had 2447 glucose readings, or an average of 3.6 glucose readings per monitored patient‐day in the preintervention period and 3.3 glucose readings per patient‐day in the postintervention period. Even including the 34 patients who were excluded for lack of glucose readings, glucose data were still available for 717 out of a potential 775 patient‐days (93%). Characteristics for all included patients are shown in Table 2. The mean admission glucose was 197 mg/dL, mean A1C was 8.4%, 54% of the patients were prescribed insulin prior to admission, and 7% had no prior diagnosis of diabetes. There were no significant differences in baseline characteristics between the 2 patient groups except for Charlson score, which was higher in the preintervention group (87% versus 74% with score 2 or higher; Table 2). The top diagnosis‐related groups for the entire cohort included: heart failure and shock (12 patients); kidney and urinary tract infections (12 patients); esophagitis, gastroenteritis, and miscellaneous digestive disorders (11 patients); chronic obstructive pulmonary disease (10 patients); renal failure (10 patients); simple pneumonia and pleurisy (7 patients); disorders of the pancreas except malignancy (6 patients); chest pain (5 patients); and cellulitis (5 patients).

Patient Characteristics
 Preintervention (n = 63)Postintervention (n = 106)P Value
  • Abbreviations: IQR, interquartile range; A1C, glycosylated hemoglobin; SD, standard deviation.

Mean age, year (SD)63.0 (15.7)64.7 (14.3)0.52
Male, n (%)25 (40)52 (49)0.27
Race, n (%)  0.33
White29 (46)42 (40) 
Black21 (33)28 (26) 
Hispanic11 (17)30 (28) 
Unknown2 (3)6 (6) 
Admission glucose, mg/dL (SD)188 (90.9)203 (96.1)0.33
A1C, % (SD)8.5 (2.4)8.3 (2.4)0.85
Insulin use prior to admission, n (%)38 (60)54 (51)0.48
Case mix index, median (IQR)0.89 (0.781.11)0.91 (0.841.22)0.33
Charlson index, n (%)  0.03
018 (13)28 (26) 
2329 (46)27 (26) 
4515 (24)29 (27) 
>511 (17)22 (21) 
Known history of diabetes, n (%)62 (98)96 (91)0.06

With respect to insulin ordering practices, there was no significant difference in the use of basal insulin in hyperglycemic patients between the preintervention period and postintervention period (81% versus 91%; P = 0.17), nor in the dose of basal insulin prescribed (results not shown), but there was an increase in the use of scheduled nutritional insulin for those patients with hyperglycemia receiving nutrition: 40% versus 75%, P < 0.001 (Table 3). The percent of patients receiving supplemental (sliding scale) insulin by itself (ie, without ever receiving basal or nutritional insulin) was lower during the postintervention period (29% versus 8%, P < 0.001). Nonsignificant differences were seen in the rates of prescribing an appropriate dose and type of nutritional insulin. Notably, there was no difference at all in the proportion of patient‐days in which insulin adjustments were made when 2 or more episodes of hyperglycemia or hypoglycemia were present during the previous day (56% of patient‐days in both groups; P = 0.90).

Study Outcomes
 Preintervention (n = 63)Postintervention (n = 106)Unadjusted Effect Size (95% CI)Adjusted Effect Size (95% CI)
  • Abbreviations: A1C, glycosylated hemoglobin; PO, eating (by mouth); SD, standard deviation.

  • Effect size is absolute percent increase in glucose readings in range, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • P < 0.05.

  • Effect size is absolute increase in mean glucose in mg/dL, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • Effect size is odds ratio for having a patient‐day with hypoglycemia, adjusted for most recent A1C and insulin use prior to admission.

  • Effect size is relative increase in length of stay, adjusted for patient insurance, race, gender, and Charlson comorbidity score.

  • Effect size is odds ratio for achieving each process measure. No multivariable adjustment was performed for process measures.

  • Excluding patients receiving a clear liquid diet, receiving enteral feeding, or receiving systemic glucocorticoid treatment.

Mean percent glucose readings 60180 mg/dL per patient (SD)59.1 (0.28)64.7 (0.27)+5.6 (3.0 to +14.3)+9.7 (+0.6 to +18.8)*,
Patient‐day weighted mean glucose, mg/dL (SD)174.7 (60.0)164.6 (54.2)10.1 (1.6 to 18.5)15.6 (6.4 to 24.9),
Percent patient‐days with any glucose <60 mg/dL16/293 (5.5%)26/424 (6.1%)1.1 (0.6 to 2.1)1.1 (0.6 to 2.1)
Percent patient‐days with any glucose <40 mg/dL3/293 (1.0%)5/424 (1.2%)1.3 (0.3 to 5.9)1.1 (0.3 to 5.1)
Hospital length of stay, hours, mean (SD)112.2 (63.3)86.0 (89.6)30% (5% to 51%)25% (6% to 44%),
Basal insulin if inpatient hyperglycemia (2 or more readings >180 mg/dL)39/48 (81%)67/74 (91%)2.2 (0.8 to 6.4) 
Nutritional insulin if inpatient hyperglycemia and PO intake19/48 (40%)53/71 (75%)4.5 (2.0 to 9.9), 
Adequate initial dose of nutritional insulin (home dose or 0.200.42 units/kg/day)#2/9 (22%)22/49 (45%)2.9 (0.5 to 15.1) 
Supplemental insulin alone (without basal or nutritional insulin)16/56 (29%)7/92 (8%)0.2 (0.08 to 0.5), 
Insulin changed if previous day's glucose out of range (2 or more values <60 or >180 mg/dL)70/126 (56%)76/135 (56%)1.0 (0.6 to 1.6) 
A1C tested during hospitalization if not available within 30 days prior38/63 (60%)74/106 (70%)1.5 (0.8 to 2.9) 

The primary outcome, the mean percent of glucose readings between 60 and 180 mg/dL per patient, was 59.1% in the preintervention period and 64.7% in the postintervention (P = 0.13 in unadjusted analysis; Table 3). When adjusted for A1C, admission glucose, and insulin use prior to admission, the adjusted absolute difference in the percent of glucose readings within range was 9.7% (95% confidence interval [CI], 0.6%‐18.8%; P = 0.04; Table 3). Regarding other measures of glucose control, the patient‐day weighted mean glucose was 174.7 mg/dL in the preintervention period and 164.6 mg/dL postintervention (P = 0.02), and there was no significant difference in the percent of patient‐days with any hypoglycemia (glucose <60 mg/dL) or severe hypoglycemia (glucose <40 mg/dL; Table 3). There were also no significant differences in the mean number of hypoglycemic events per patient‐day (6.8 versus 6.6 per 100 patient‐days; relative risk, 0.95; 95% CI, 0.541.67; P = 0.87) or severe hypoglycemic events per patient‐day (1.0 versus 1.4 per 100 patient‐days; relative risk, 1.38; 95% CI, 0.355.53; P = 0.65).

We also compared hospital length of stay in hours between the study groups (Table 3). Length of stay (LOS) was shorter in the postintervention arm in unadjusted analyses (112 versus 86 hours; P < 0.001), and this difference persisted when adjusted for patient insurance, race, gender, and Charlson comorbidity score (25% shorter; 95% CI, 6%‐44%). A comparison of LOS among nonstudy patients on the PACE service during these 2 time periods revealed no difference (105 versus 101 hours). When the length of stay analysis was limited to study patients with a known diagnosis of diabetes, the adjusted effect size was a 31% relative decrease in length of stay.

Figure 1A shows the percent glucose readings within range per patient by hospital day. The greatest differences between groups can be seen on hospital days 2 and 3 (11% absolute differences on both days). Similarly, Figure 1B shows the mean glucose per patient by hospital day. Again, the biggest differences are seen on hospital days 2 and 3 (20 and 23 mg/dL difference between groups, respectively). In both cases, only the day 3 comparisons were significantly different between study groups.

Figure 1
Diagnostic and treatment algorithm for sleep in hospitalized medical patients.

DISCUSSION

In this before‐after study, we found that a multifaceted intervention consisting of a subcutaneous insulin protocol, focused education, and an order set built into the hospital's CPOE system was associated with a significantly higher percentage of glucose readings within range per patient in analyses adjusted for patient demographics and severity of diabetes. We also found a significant decrease in patient‐day weighted mean glucose, a marked increase in appropriate use of scheduled nutritional insulin, and a concomitant decrease in sliding scale insulin only regimens during the postintervention period. Moreover, we found a shorter length of stay during the postintervention period that persisted after adjustment for several clinical factors. Importantly, the interventions described in this study require very few resources to continue indefinitely: printing costs for the management protocol, 4 hours of education delivered per year, and routine upkeep of an electronic order set.

Because this was a before‐after study, we cannot exclude the possibility that these improvements in process and outcome were due to cointerventions and/or temporal trends. However, we know of no other interventions aimed at improving diabetes care in this self‐contained service of nurses, PAs, and hospitalists. Moreover, the process improvements, especially the increase in scheduled nutritional insulin, were rather marked, unlikely to be due to temporal trends alone, and likely capable of producing the corresponding improvements in glucose control. That glucose control stopped improving after hospital day 3 may be due to the fact that subsequent adjustment to insulin orders occurred infrequently and no more often than prior to the intervention. That we did not see greater improvements in glycemic control overall may also reflect the fact that 81% of study patients with inpatient hyperglycemia received basal insulin prior to the intervention.

The reduction in patient LOS was somewhat surprising given the relatively small sample size. However, the results are consistent with those of other studies linking hyperglycemia to LOS18, 19 and we found no evidence for a temporal trend toward lower LOS on the PACE service as a whole during the same time period. While a greater proportion of patients on the PACE service were in the study in the post‐intervention period compared with the preintervention period, we found no evidence that the difference in length of stay was due to increased surveillance for nondiabetics, especially because eligibility criteria depended on phlebotomy glucose values, which were uniformly tested in all inpatients. Also, effects on length of stay were actually stronger when limited to patients with known diabetes. Finally, we controlled for several predictors of length of stay, although we still cannot exclude the possibility of unmeasured confounding between groups.

Since ADA and ACE issued guidelines for inpatient management of diabetes and hyperglycemia, many institutions have developed subcutaneous insulin algorithms, educational curricula, and/or order sets to increase compliance with these guidelines and improve glycemic control. Some of these efforts have been studied and some have been successful in their efforts.13, 14, 2023 Unfortunately, most of these programs have not rigorously assessed their impact on process and outcomes, and the most effective studies published to date have involved interventions much more intensive than those described here. For example, Rush University's intervention was associated with a 50 mg/dL decrease in mean blood glucose but involved an endocrinologist rounding twice daily with house officers for 2 weeks at a time.13 At Northwestern University, a diabetes management service run by nurse practitioners was established, and the focus was on the conversion from intravenous to subcutaneous insulin regimens.14 The RABBIT 2 study that demonstrated the benefits of a basal‐bolus insulin regimen used daily rounding with an endocrinologist.12 More modestly, a program in Pitt County Memorial Hospital in Greenville, NC, relied mostly on diabetes nurse case managers, a strategy which reduced hospital‐wide mean glucose levels as well as LOS, although the greatest improvements in glycemic control were seen in the ICU.19 Our findings are much more consistent with those from University of California San Diego, as yet unpublished, which also used an algorithm, computerized order set, education, as well as continuous quality improvement methods to achieve its aims.22

Our study has several limitations, including being conducted on 1 general medicine service at 1 academic medical center. Moreover, this service, using a physician assistant/hospitalist model, a closed geographic unit, and fairly generous staffing ratio, is likely different from those in many settings and may limit the generalizability of our findings. However, this model allowed us to conduct the study in a laboratory relatively untouched by other cointerventions. Furthermore, the use of PAs in this way may become more common as both academic and community hospitals rely more on mid‐level providers. Our study had a relatively low percentage of patients without a known diagnosis of diabetes compared with other studies, again potentially but not necessarily limiting generalizability. This finding has been shown in other studies at our institution24 and may be due to the high rate of screening for diabetes in the community. Another limitation is that this was a nonrandomized, before‐after trial. However, all subjects were prospectively enrolled to improve comparability, and we performed rigorous adjustment for multiple potential confounding factors. Also, this study had limited statistical power to detect differences in hypoglycemia rates. The preintervention arm was smaller than planned due to fewer diabetic patients than expected on the service and a higher number of exclusions; we prolonged the postintervention period to achieve the desired sample size for that arm of the study.

Our study also has several strengths, including electronic capture of many processes of care and a methodology to operationalize them into measures of protocol adherence. Our metrics of glycemic control were rigorously designed and based on a national task force on inpatient glycemic control sponsored by the Society of Hospital Medicine, with representation from the ADA and AACE.25

Potential future improvements to this intervention include modifications to the daily adjustment algorithm to improve its usability and ability to improve glucose control. Another is the use of high‐reliability methods to improve order set use and daily insulin adjustment, including alerts within the CPOE system and nurse empowerment to contact medical teams if glucose levels are out of range (eg, if greater than 180 mg/dL, not just if greater than 350 or 400 mg/dL). Future research directions include multicenter, randomized controlled trials of these types of interventions and an analysis of more distal patient outcomes including total healthcare utilization, infection rates, end‐organ damage, and mortality.

In conclusion, we found a relationship between a relatively low‐cost quality improvement intervention and improved glycemic control in the non‐ICU general medical setting. Such a finding suggests the benefits of the algorithm itself to improve glucose control and of our implementation strategy. Other institutions may find this intervention a useful starting point for their own quality improvement efforts. Both the algorithm and implementation strategy are deserving of further improvements and future study.

Acknowledgements

We thank Paul Szumita, Karen Fiumara, Jennifer Trujillo, and the other members of the BWH Diabetes Pharmacy and Therapeutics Subcommittee for their help designing and implementing the intervention; Aubre McClendon, Nicole Auclair, Emily Dattwyler, Mariya Fiman, and Alison Pietras for valuable research assistance; Deborah Williams for data analysis; Amy Bloom for project support; and Stuart Lipsitz for biostatistical expertise.

APPENDIX

INPATIENT DIABETES MANAGEMENT PROTOCOL

Management of Diabetes and Hyperglycemia in Hospitalized Non‐ICU Patients

Rationale

Increasing data show a strong association between hyperglycemia and adverse inpatient outcomes. The American Diabetes Association and the American College of Clinical Endocrinology recommend all glucose levels be below 180 mg/dL in non‐ICU patients. Because hospitalizations are unstable situations, even patients who are well controlled on oral agents as outpatients are usually best managed with insulin.

Insulin may be safely administered even to patients without previously diagnosed diabetes. As long as the prescribed doses are below what is normally produced by the pancreas, the patient will not become hypoglycemic. If the glucose level drops, endogenous insulin secretion will reduce to compensate.

Total insulin requirements in insulin‐sensitive patients (eg, type 1 diabetes mellitus) is 0.50.7/units/kg/day. Insulin requirements in insulin‐resistant type 2 diabetic patients may vary greatly, and can exceed 12 units/kg/day. A conservative estimate for initial insulin therapy in any patient with diabetes is to start with the type 1 diabetes mellitus dose, 0.50.7 units/kg/day.

Overview

Effective inpatient insulin regimens typically include 3 components:

  • Basal insulin (eg, scheduled NPH or insulin glargine [Lantus]), which is used to manage fasting and premeal hyperglycemia.

  • Nutritional or prandial insulin (eg, scheduled regular insulin, insulin lispro [Humalog] or insulin aspart [Novolog]) which controls hyperglycemia from nutritional (eg, discrete meals, TPN, IV dextrose) sources.

  • Supplemental or correctional insulin (eg, regular insulin, insulin lispro, or insulin aspart), which is used in addition to scheduled insulin to meet unexpected basal hyperglycemia that is not covered by the scheduled insulin.

 

Sample Orders (Not for Patients with Uncontrolled Type 1 Diabetes, DKA, Hyperglycemic Hyperosmolar State, or Other Absolute Need for IV Insulin)

 

  • Check (fingerstick) capillary blood glucose qAC, qHS.

  • NPH insulin subcutaneously (SC) ___ units qAM, ___ units qHS.

  • Insulin aspart SC ___ units pre‐breakfast, ___ units pre‐lunch, ___ units pre‐dinner, hold if NPO or premeal BS <60 mg/dL; give 015 minutes before meals.

  • Insulin aspart SC sliding scale (see Table 6) qAC, in addition to standing nutritional insulin, 015 minutes before meals.

  • For BS <60 mg/dL:

     

    • If patient can take PO

       

      • Give 15 g of fast acting carbohydrate (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets).

      • Repeat finger capillary glucose every 15 (q15) minutes and repeat above (5.a.i.) if BG <60 mg/dL.

      • When BG >60 mg/dL, give snack or meal in a half‐hour.

      • If patient cannot take PO

         

        • Give 25 mL of 50% dextrose (D50) as an IV push.;

        • Repeat finger capillary glucose q15 minutes and repeat above (5.b.i.) if BG <80 mg/dL.

         

Guidelines

 

  • Stop oral diabetes agents in most patients (see Table 7 for list of contraindications and precautions).

  • Check bedside blood glucose (BBG or fingerstick) qAC and qHS (or at 0600 hours, 1200 hours, 1800 hours, and 2400 hours if no discrete meals).

  • Estimate total daily insulin requirement:

     

    • For most patients, conservative estimate is 0.50.7 units/kg/day, but may be much higher.

    • Reasons for lower end of the range: renal insufficiency, small size, insulin sensitive (eg, type 1), recent hypoglycemia, decreasing doses of steroids, older age.

    • Reasons for higher end of the range: obese, initiation or increasing doses of steroids, marked hyperglycemia.

    • Start basal insulin if any premeal BG >140 mg/dL and no recent glucose <60 mg/dL off insulin (Table 5).

    • Start nutritional or prandial insulinhold if nutrition is stopped/held or premeal BS <60 (Table 5).

    • Start supplemental/correctional insulin in addition to nutritional (prandial) insulin (Table 6):

       

      • Discrete meals: Insulin aspart qAC (with nutritional insulin). 0

      • No discrete meals: Regular insulin q6h.

      • On a daily basis, adjust scheduled insulin based on previous days' blood sugars:

         

        • Add up total insulin given the previous day, including scheduled and supplemental insulin, to determine new total daily insulin requirement.

        • Adjust total daily insulin requirement based on clinical considerations (eg, give more if marked hyperglycemia, eating more, improving renal function, increasing steroids; give less if eating less, worsening renal function, tapering steroids, recovering from severe illness).

        • Give 50% of requirement as basal and 50% as nutritional, as above (may need proportionately less nutritional insulin if appetite poor or unknown).

        • Adjust sliding scale if needed based on total scheduled insulin dose (see step 6, above).

        • For BG <60 mg/dL:

           

          • If patient can take PO, give 15 g of fast acting carbohydrate.

          • (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets; not juice plus sugar).

          • Repeat finger capillary glucose q15 minutes and repeat above if BG <60.

          • When BG >60, give snack or meal in half an hour.

          • If patient cannot take PO, give 25 mL of D50 as IV push.

          • Check finger capillary glucose q15 minutes and repeat above if BG <80.

          • Discharge orders:

             

            • Patient should be discharged home on a medication regimen that was similar to the admission regimen (ie, the regimen prescribed by their PCP). Exceptions include

               

              • The patient has a contraindication to an admission medication.

              • There is evidence of severe hyperglycemia (eg, very high A1C) or hypoglycemia on admission regimen.

              • If a patient is admitted with no insulin, and requires insulin to be continued as an outpatient (eg, newly‐diagnosed type 1 diabetes, A1C very high, and contraindication to or on maximum oral regimen), limit discharge insulin regimen to no more than 1 injection per day (eg, hs NPH; an exception to this is for type 1 diabetic patients, who are optimally treated with 34 injections/day). Make sure the patient has prompt follow‐up with their primary care provider (PCP).

              • Avoid discharging home on sliding scale.

              • If a patient is going to require insulin injections and self‐monitoring blood glucose as an outpatient, make sure they are instructed about how to perform these.

              • Indications for calling an endocrine consult:

                 

                • Labile blood sugars.

                • Prolonged periods of NPO, eg, for procedures, especially in patients with type 1 diabetes

                • Marked hyperglycemia despite following this guideline.

                • Question of type 1 versus type 2 versus other type of diabetes. 0

                 

                Basil Insulin Guidelines
                Home Insulin RegimenStarting Dose of Basal InsulinConsiderations
                • NOTE: Patients with T1DM require basal insulin at all times! Basal never should be held!

                • Abbreviations: NPO, nothing by mouth.

                On basal (eg, NPH or glargine) insulin at homePatient's home dose of NPH or glargineIf NPO, consider starting half of NPH or glargine home dose, unless hyperglycemic at home.
                Not on basal (eg, NPH or glargine) insulin at homeNPH 50% of total daily insulin requirement, given qHS or split qAM/qHS (maximum starting dose 20 units/day)Same dose if patient has previously diagnosed or undiagnosed diabetes
                Nutritional Insulin Guidelines
                Type of NutritionCommon Nutritional RegimensSample Starting Doses
                • Abbreviation: qAM, every morning; qHS, at bed time.

                • If receiving cycled tube feeds at night, give nutritional NPH qHS only.

                Discrete mealsAspart given 015 minutes before mealsHome dose, if known or
                50% of total insulin requirement, split over 3 meals, may need less if poor or unknown appetite
                Continuous tube feeding,* IV dextroseNPH qHS or qAM/qHS50% of total insulin requirement (in addition to basal dose), may need less if not at goal caloric intake
                Glargine given every day (qd), anytime
                Regular every 6 hours (q6h)
                Sample Supplemental/Correctional Insulin Scales
                Blood GlucoseScheduled Insulin < 40 Units/DayScheduled Insulin of 4080 Units/DayScheduled Insulin > 80 Units/DayIndividualized
                • NOTE: Avoid supplemental insulin qHS unless patient is very hyperglycemic and obese.

                1501991 unit1 unit2 units____ units
                2002492 units3 units4 units____ units
                2502993 units5 units7 units____ units
                3003494 units7 units10 units____ units
                >3495 units + call HO8 units + call HO12 units + call HO___ units + call HO
                Notes on Oral Agents
                AgentsConsiderationsMetabolism
                Sulfonylureas/secretagogues: glyburide, glipizide, glimeperide (Amaryl); repaglinide (Prandin); nateglinide (Starlix)Risk for hypoglycemiaMetabolized in liver; Glyburide metabolized to active metabolites; 50% renally eliminated
                MetforminContraindicated in heart failure and renal dysfunction (creatinine [Cr] >1.5 mg/dL in men and 1.4 mg/dL in women)Eliminated renally
                Should be held at time of iodinated contrast studies. (May be restarted after normal postcontrast renal function is confirmed)
                Adverse effects include diarrhea, nausea, and anorexia
                Thiazolidinediones: pioglitazone (Actos), rosiglitazone (Avandia)Contraindicated in class III and IV heart failureMetabolized in liver
                Use with caution in patients with edema
                Adverse effects include increased intravascular volume
                Slow onset of action
                Avoid in hepatic dysfunction
                Glucosidease inhibitors: acarbose (Precose), miglitol (Glycet)Gastrointestinal intoleranceAcarbose eliminated in gut and renally

Diabetes mellitus and/or inpatient hyperglycemia are common comorbid conditions in hospitalized patients. Recent surveys show that over 90% of hospitalized diabetic patients experience hyperglycemia (>200 mg/dL), and in nearly 1 in 5 of these patients hyperglycemia persists for 3 days or more.1 Hyperglycemia among inpatients without a previous history of diabetes mellitus is also very common.2 Observational studies have shown that hyperglycemia in hospitalized patients is associated with adverse outcomes including infectious complications, increased length of stay, and increased mortality.27 Recent randomized controlled trials have demonstrated that aggressive treatment of inpatient hyperglycemia improves outcomes in surgical and medical intensive care units.8, 9

Based on the available data, the American Diabetes Association (ADA) now advocates good metabolic control, defined as preprandial glucose levels of 90 to 130 mg/dL and peak postprandial glucose levels <180 mg/dL in hospitalized nonintensive care unit (ICU) patients.10 To reach these targets, the ADA and American College of Endocrinology (ACE) suggest that multidisciplinary teams develop and implement hyperglycemia management guidelines and protocols.11 Protocols should promote the use of continuous intravenous insulin infusions or scheduled basal‐bolus subcutaneous insulin regimens. Subcutaneous insulin protocols should include target glucose levels, basal, nutritional, and supplemental insulin, and daily dose adjustments.6 A recent randomized controlled trial of non‐ICU inpatients demonstrated that such a basal‐bolus insulin regimen results in improved glucose control compared with a sliding scale only regimen.12

To date, few published studies have investigated the best ways to implement such management protocols; those that have are often resource‐intensive, for example involving daily involvement of nurse practitioners or diabetologists.13, 14 It is therefore not known how best to implement an inpatient diabetes management program that is effective, efficient, and self‐perpetuating. At Brigham and Women's Hospital (BWH), we have been refining a subcutaneous insulin protocol, focused provider education, and more recently a computerized order set to overcome barriers related to fear of hypoglycemia, delays in insulin prescribing, and unfamiliarity with inpatient glucose management.15 The aims of this current trial were to evaluate the effects of these interventions on a geographically localized general medical service previously naive to these interventions to evaluate their effects on glycemic control, patient safety, and processes of care. We hypothesized that these interventions would improve glycemic control and increase use of basal‐bolus insulin orders without increasing the rate of hypoglycemia.

METHODS

Setting and Participants

This prospective, before‐after trial was conducted at BWH from July 15, 2005 through June 22, 2006. Eligible subjects were patients scheduled for admission to the BWH Physician Assistant/Clinician Educator (PACE) Service with either a known diagnosis of type 2 diabetes mellitus or inpatient hyperglycemia (at least 1 random laboratory glucose >180 mg/dL). The PACE service is a geographically‐localized general medicine service of up to 15 beds where patients are cared for by a single cadre of nurses, 2 physician's assistants (PAs), and 1 hospitalist attending. A moonlighter covers the service at night. The PACE service does not accept patients transferred from other acute care hospitals or from ICUs, but does not otherwise have triage guidelines related to diagnosis, complexity, or acuity. Patients were excluded if they had type 1 diabetes, presented with hyperosmolar hyperglycemic state (HHS) or diabetic ketoacidosis (DKA), received total parenteral nutrition (TPN), or were receiving palliative care. This study was approved by the BWH Institutional Review Board; patient consent was deemed not to be necessary for this study given the relatively nonsensitive nature of the data, noninvasive means of data collection, and the steps taken by research personnel to minimize any breach in patient confidentiality.

Intervention

The study intervention consisted of three components, initiated in January 2006:

  • Glycemic management protocol: a multidisciplinary team of a diabetologist (M.L.P.), a hospitalist (J.L.S.), and a pharmacist (Jennifer Trujillo) developed a subcutaneous insulin protocol based on ADA guidelines (Table 1; see the appendix for complete protocol). The protocol was approved by the BWH Pharmacy and Therapeutics Diabetes Subcommittee and refined through 6 months of pilot testing on other general medical services.15 The protocol consisted of a set of specific treatment recommendations, including: (1) bedside glucose monitoring; (2) stopping oral diabetes agents in most patients; (3) estimating total daily insulin requirements; (4) prescribing basal, nutritional, and supplemental insulin based on the patient's total insulin requirements, preadmission medication regimen, and nutritional status; (5) adjusting insulin on a daily basis as needed; (6) managing hypoglycemia; (7) suggestions for discharge orders; and (8) indications for an endocrinology consultation. The protocol was printed as a pocket guide, distributed to all members of the PACE service, and used to guide all other interventions.

  • Diabetes education: all PAs received 2 one‐hour educational sessions: a lecture by a diabetologist (M.L.P.) reviewing the rationale for tight glycemic control and general principles of management, and a workshop by a hospitalist (J.L.S.) in which specific cases were reviewed to illustrate how the protocol could be used in practice (eg, when oral agents could be safely continued, how to prescribe insulin on admission, and how to make subsequent adjustments in dose). All hospitalist attendings received a 1‐hour lecture summarizing the above material. All nurses on the service received a lecture that focused on issues unique to nursing care, such as insulin administration, glucose testing, managing patients with unpredictable oral (PO) intake, and patient education. (All materials are available from the authors upon request).

  • Order Set: an order set, built into BWH's proprietary computer provider order entry (CPOE) system, was created to parallel the glycemic management protocol and facilitate insulin orders for patients eating discrete meals, receiving continuous liquid enteral nutrition (tube feeds), or receiving nothing by mouth (NPO). Other components of the order set facilitated glucose monitoring and other laboratory tests and ordering consultation when appropriate.

 

Summary of Inpatient Diabetes Management Protocol
Oral AgentsStop Oral Agents in Most Patients
  • NOTE: See the Appendix for full description of insulin protocol.

  • Abbreviations: A1C, glycosylated hemoglobin; IM, intramuscular; IV, intravenous; NPO, not eating (nothing by mouth); PO, eating (by mouth); qAM, every morning, qHS, at bedtime.

Glucose testingCheck bedside blood glucose before meals and at bedtime if eating, or every 6 hours if NPO
Insulin 
1. Estimate total daily insulin dose0.5 to 0.7 units/kg/day, depending on patient's age, size, renal function, insulin sensitivity, history of hypoglycemia, and steroid use
2. Start basal insulinPatient's home dose or 50% of calculated total daily dose; NPH qAM/qHS or insulin glargine qHS; If NPO, use one‐half the home dose unless hyperglycemic
3. Start nutritional insulin if not NPOPatient's home dose or 50% of calculated total daily dose, less if poor or unknown intake; discrete meals: insulin aspart split over 3 meals, 0 to 15 minutes prior to eating; continuous tube feeds or IV dextrose: regular insulin every 6 hours
4. Start correctional insulin1 of 3 scales provided based on total daily dose of insulin; same type as nutritional insulin; regular insulin if NPO
5. Daily adjustmentCalculate total administered dose from prior day, adjust for degree of hyperglycemia or hypoglycemia, renal function, PO intake, steroid use, and degree of illness, and redistribute as 50% basal, 50% nutritional, or 100% basal if NPO
Hypoglycemia ordersJuice, IV dextrose, or IM glucagon depending on ability to take oral nutrition and IV access
Discharge ordersBased on A1C: either home regimen, titration of home regimen, or new insulin regimen (if latter, simple regimen with aggressive patient education and prompt follow‐up)
Indications for endocrine consultationLabile blood sugars, poor control, prolonged NPO period, question of type 1 or type 2 diabetes

Study Protocol and Data Collection

A research assistant prospectively identified eligible patients each weekday by screening all patients scheduled for admission to the PACE service using the daily computerized sign‐out system used on all general medical teams. Specifically, laboratory random glucose levels, inpatient medications, and medical histories were reviewed to determine if each patient met eligibility criteria. Eligibility criteria were then confirmed by medical record review and adjudicated by one study author (J.L.S.) if necessary. Further medical record review was performed to identify specific patient populations (eg, diet‐controlled, steroid‐induced, or previously undiagnosed diabetes), determine preadmission diabetes medications, and determine the patient's weight. Hospital computerized clinical and administrative records were abstracted to obtain patient demographics (age, sex, race, insurance status), laboratory data (glucose level on admission, A1C level [taken during or within 6 months prior to admission]), clinical data (length of stay, billing‐based Charlson comorbidity score,16 and diagnosis‐related group [DRG] case mix index), all inpatient insulin and oral diabetes medication orders, frequency of bedside glucose testing, and diet orders. Electronic medication administration record (eMAR) data were used to determine all doses and times of insulin administration.

Outcomes

The primary outcome was the mean percent of glucose readings between 60 and 180 mg/dL per patient (ie, calculated for each patient and averaged across all eligible patients in each study arm). Only bedside glucose readings were used given the lack of additional useful information typically provided by laboratory (venous plasma) glucose readings.17 Readings drawn within 1 hour of a previous reading were excluded to avoid ascertainment bias caused by follow‐up testing of abnormal glucose values. Only readings while on the study service were used. Readings on hospital day 1 were excluded because our intervention was expected to have little impact on the first day's glucose control; for patients with undiagnosed diabetes, data collection began the day following the first elevated glucose reading. Readings beyond hospital day 14 were also excluded to avoid biased data from patients with exceptionally long lengths of stay.

Secondary outcomes included the following:

  • Glycemic control:

     

    • Patient‐day weighted mean glucose (ie, mean glucose for each patient‐day, averaged across all patient days);

    • Mean glucose per patient for each hospital day (days 17).

    • Patient safety:

       

      • Proportion of patient‐days with any glucose reading <60 mg/dL (hypoglycemia) and <40 mg/dL (severe hypoglycemia).

      • Processes of care:

         

        • Use of any NPH insulin or insulin glargine (basal) insulin during the hospitalization if 2 or more glucose readings were >180 mg/dL.

        • Adequacy of basal dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission basal dose or 0.20 to 0.42 units/kg if not known or not taken prior to admission. If not eating, half the above calculations.

        • Use of any scheduled nutritional insulin during the hospitalization if ever prescribed a diet and 2 or more glucose readings were greater than 180 mg/dL.

        • Adequacy of nutritional dose on day first prescribed: for patients prescribed a diet, within 20% of preadmission nutritional dose or 0.20 to 0.42 units/kg/day if not known or not taken prior to admission. Patients on clear liquid diets, enteral feeds, or receiving glucocorticoids were excluded from this analysis.

        • Correct type of nutritional insulin: if eating discrete meals, insulin aspart (the rapid‐acting insulin on formulary at BWH); if prescribed tube feeds, regular insulin.

        • Use of supplemental insulin by itself (without scheduled basal or nutritional insulin), a marker of poor care.

        • A1C testing within 1 month prior to or during hospitalization.

        • Clinical inertia: if at least two glucose readings <60 mg/dL or >180 mg/dL on a patient‐day, lack of any change to any insulin order the following day if still on the study service.

        • Healthcare utilization:

           

          • Hospital length of stay in hours, calculated from the exact time of admission until the exact time of discharge, using hospital administrative data.

           

Analyses

Study results were compared prior to the intervention (July 15 through December 12, 2005) with those during the intervention (January 18 through June 20, 2006). Patient data and clinical outcomes were analyzed descriptively using proportions, means with standard deviations (SDs), or medians with interquartile ranges (IQRs) as appropriate. Comparisons between groups were calculated using Fisher's exact test for dichotomous and categorical variables, and Student t test or Wilcoxon rank sum test for continuous variables as appropriate. The primary outcome was first analyzed using linear regression with study group as the independent variable and percent of glucose readings within range per patient as the dependent variable. We then adjusted for potential confounders by putting each covariate into the model, one at a time. All significant predictors of the outcome at a P value <0.10 were retained in the final model. We used general estimating equations to adjust for clustering of results by each PA. Similar analyses were performed for hospital length of stay per patient using a negative binomial model, so chosen because it fit the data distribution much better than the typically used Poisson model. With a planned sample size of 115 patients and 1250 glucose readings per arm, an intraclass correlation coefficient of 0.10, and an alpha of 0.05, the study had 90% power to detect an increase in percent of glucose readings in range from 67% to 75%. All analyses were based on the intention‐to‐treat principle. Except as above, 2‐sided P values <0.05 were considered significant. SAS version 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

We prospectively identified 248 potential patients for the study. We subsequently excluded 79 patients for the following reasons: no glucose readings beyond hospital day 1 while on PACE service (34 patients); never admitted to PACE service (15 patients); no diabetes or inpatient hyperglycemia (9 patients, mostly patients prescribed an insulin sliding scale prophylactically to avoid steroid‐induced hyperglycemia); type 1 diabetes (13 patients); TPN, DKA, or HHS (5 patients); and palliative care (3 patients). The remaining 169 patients included 63 from the preintervention period(out of 489 total admissions to the PACE service; 13%) and 106 patients in the postintervention period (out of 565 admissions; 19%). These patients had 2447 glucose readings, or an average of 3.6 glucose readings per monitored patient‐day in the preintervention period and 3.3 glucose readings per patient‐day in the postintervention period. Even including the 34 patients who were excluded for lack of glucose readings, glucose data were still available for 717 out of a potential 775 patient‐days (93%). Characteristics for all included patients are shown in Table 2. The mean admission glucose was 197 mg/dL, mean A1C was 8.4%, 54% of the patients were prescribed insulin prior to admission, and 7% had no prior diagnosis of diabetes. There were no significant differences in baseline characteristics between the 2 patient groups except for Charlson score, which was higher in the preintervention group (87% versus 74% with score 2 or higher; Table 2). The top diagnosis‐related groups for the entire cohort included: heart failure and shock (12 patients); kidney and urinary tract infections (12 patients); esophagitis, gastroenteritis, and miscellaneous digestive disorders (11 patients); chronic obstructive pulmonary disease (10 patients); renal failure (10 patients); simple pneumonia and pleurisy (7 patients); disorders of the pancreas except malignancy (6 patients); chest pain (5 patients); and cellulitis (5 patients).

Patient Characteristics
 Preintervention (n = 63)Postintervention (n = 106)P Value
  • Abbreviations: IQR, interquartile range; A1C, glycosylated hemoglobin; SD, standard deviation.

Mean age, year (SD)63.0 (15.7)64.7 (14.3)0.52
Male, n (%)25 (40)52 (49)0.27
Race, n (%)  0.33
White29 (46)42 (40) 
Black21 (33)28 (26) 
Hispanic11 (17)30 (28) 
Unknown2 (3)6 (6) 
Admission glucose, mg/dL (SD)188 (90.9)203 (96.1)0.33
A1C, % (SD)8.5 (2.4)8.3 (2.4)0.85
Insulin use prior to admission, n (%)38 (60)54 (51)0.48
Case mix index, median (IQR)0.89 (0.781.11)0.91 (0.841.22)0.33
Charlson index, n (%)  0.03
018 (13)28 (26) 
2329 (46)27 (26) 
4515 (24)29 (27) 
>511 (17)22 (21) 
Known history of diabetes, n (%)62 (98)96 (91)0.06

With respect to insulin ordering practices, there was no significant difference in the use of basal insulin in hyperglycemic patients between the preintervention period and postintervention period (81% versus 91%; P = 0.17), nor in the dose of basal insulin prescribed (results not shown), but there was an increase in the use of scheduled nutritional insulin for those patients with hyperglycemia receiving nutrition: 40% versus 75%, P < 0.001 (Table 3). The percent of patients receiving supplemental (sliding scale) insulin by itself (ie, without ever receiving basal or nutritional insulin) was lower during the postintervention period (29% versus 8%, P < 0.001). Nonsignificant differences were seen in the rates of prescribing an appropriate dose and type of nutritional insulin. Notably, there was no difference at all in the proportion of patient‐days in which insulin adjustments were made when 2 or more episodes of hyperglycemia or hypoglycemia were present during the previous day (56% of patient‐days in both groups; P = 0.90).

Study Outcomes
 Preintervention (n = 63)Postintervention (n = 106)Unadjusted Effect Size (95% CI)Adjusted Effect Size (95% CI)
  • Abbreviations: A1C, glycosylated hemoglobin; PO, eating (by mouth); SD, standard deviation.

  • Effect size is absolute percent increase in glucose readings in range, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • P < 0.05.

  • Effect size is absolute increase in mean glucose in mg/dL, adjusted for admission glucose, most recent A1C, and insulin use prior to admission.

  • Effect size is odds ratio for having a patient‐day with hypoglycemia, adjusted for most recent A1C and insulin use prior to admission.

  • Effect size is relative increase in length of stay, adjusted for patient insurance, race, gender, and Charlson comorbidity score.

  • Effect size is odds ratio for achieving each process measure. No multivariable adjustment was performed for process measures.

  • Excluding patients receiving a clear liquid diet, receiving enteral feeding, or receiving systemic glucocorticoid treatment.

Mean percent glucose readings 60180 mg/dL per patient (SD)59.1 (0.28)64.7 (0.27)+5.6 (3.0 to +14.3)+9.7 (+0.6 to +18.8)*,
Patient‐day weighted mean glucose, mg/dL (SD)174.7 (60.0)164.6 (54.2)10.1 (1.6 to 18.5)15.6 (6.4 to 24.9),
Percent patient‐days with any glucose <60 mg/dL16/293 (5.5%)26/424 (6.1%)1.1 (0.6 to 2.1)1.1 (0.6 to 2.1)
Percent patient‐days with any glucose <40 mg/dL3/293 (1.0%)5/424 (1.2%)1.3 (0.3 to 5.9)1.1 (0.3 to 5.1)
Hospital length of stay, hours, mean (SD)112.2 (63.3)86.0 (89.6)30% (5% to 51%)25% (6% to 44%),
Basal insulin if inpatient hyperglycemia (2 or more readings >180 mg/dL)39/48 (81%)67/74 (91%)2.2 (0.8 to 6.4) 
Nutritional insulin if inpatient hyperglycemia and PO intake19/48 (40%)53/71 (75%)4.5 (2.0 to 9.9), 
Adequate initial dose of nutritional insulin (home dose or 0.200.42 units/kg/day)#2/9 (22%)22/49 (45%)2.9 (0.5 to 15.1) 
Supplemental insulin alone (without basal or nutritional insulin)16/56 (29%)7/92 (8%)0.2 (0.08 to 0.5), 
Insulin changed if previous day's glucose out of range (2 or more values <60 or >180 mg/dL)70/126 (56%)76/135 (56%)1.0 (0.6 to 1.6) 
A1C tested during hospitalization if not available within 30 days prior38/63 (60%)74/106 (70%)1.5 (0.8 to 2.9) 

The primary outcome, the mean percent of glucose readings between 60 and 180 mg/dL per patient, was 59.1% in the preintervention period and 64.7% in the postintervention (P = 0.13 in unadjusted analysis; Table 3). When adjusted for A1C, admission glucose, and insulin use prior to admission, the adjusted absolute difference in the percent of glucose readings within range was 9.7% (95% confidence interval [CI], 0.6%‐18.8%; P = 0.04; Table 3). Regarding other measures of glucose control, the patient‐day weighted mean glucose was 174.7 mg/dL in the preintervention period and 164.6 mg/dL postintervention (P = 0.02), and there was no significant difference in the percent of patient‐days with any hypoglycemia (glucose <60 mg/dL) or severe hypoglycemia (glucose <40 mg/dL; Table 3). There were also no significant differences in the mean number of hypoglycemic events per patient‐day (6.8 versus 6.6 per 100 patient‐days; relative risk, 0.95; 95% CI, 0.541.67; P = 0.87) or severe hypoglycemic events per patient‐day (1.0 versus 1.4 per 100 patient‐days; relative risk, 1.38; 95% CI, 0.355.53; P = 0.65).

We also compared hospital length of stay in hours between the study groups (Table 3). Length of stay (LOS) was shorter in the postintervention arm in unadjusted analyses (112 versus 86 hours; P < 0.001), and this difference persisted when adjusted for patient insurance, race, gender, and Charlson comorbidity score (25% shorter; 95% CI, 6%‐44%). A comparison of LOS among nonstudy patients on the PACE service during these 2 time periods revealed no difference (105 versus 101 hours). When the length of stay analysis was limited to study patients with a known diagnosis of diabetes, the adjusted effect size was a 31% relative decrease in length of stay.

Figure 1A shows the percent glucose readings within range per patient by hospital day. The greatest differences between groups can be seen on hospital days 2 and 3 (11% absolute differences on both days). Similarly, Figure 1B shows the mean glucose per patient by hospital day. Again, the biggest differences are seen on hospital days 2 and 3 (20 and 23 mg/dL difference between groups, respectively). In both cases, only the day 3 comparisons were significantly different between study groups.

Figure 1
Diagnostic and treatment algorithm for sleep in hospitalized medical patients.

DISCUSSION

In this before‐after study, we found that a multifaceted intervention consisting of a subcutaneous insulin protocol, focused education, and an order set built into the hospital's CPOE system was associated with a significantly higher percentage of glucose readings within range per patient in analyses adjusted for patient demographics and severity of diabetes. We also found a significant decrease in patient‐day weighted mean glucose, a marked increase in appropriate use of scheduled nutritional insulin, and a concomitant decrease in sliding scale insulin only regimens during the postintervention period. Moreover, we found a shorter length of stay during the postintervention period that persisted after adjustment for several clinical factors. Importantly, the interventions described in this study require very few resources to continue indefinitely: printing costs for the management protocol, 4 hours of education delivered per year, and routine upkeep of an electronic order set.

Because this was a before‐after study, we cannot exclude the possibility that these improvements in process and outcome were due to cointerventions and/or temporal trends. However, we know of no other interventions aimed at improving diabetes care in this self‐contained service of nurses, PAs, and hospitalists. Moreover, the process improvements, especially the increase in scheduled nutritional insulin, were rather marked, unlikely to be due to temporal trends alone, and likely capable of producing the corresponding improvements in glucose control. That glucose control stopped improving after hospital day 3 may be due to the fact that subsequent adjustment to insulin orders occurred infrequently and no more often than prior to the intervention. That we did not see greater improvements in glycemic control overall may also reflect the fact that 81% of study patients with inpatient hyperglycemia received basal insulin prior to the intervention.

The reduction in patient LOS was somewhat surprising given the relatively small sample size. However, the results are consistent with those of other studies linking hyperglycemia to LOS18, 19 and we found no evidence for a temporal trend toward lower LOS on the PACE service as a whole during the same time period. While a greater proportion of patients on the PACE service were in the study in the post‐intervention period compared with the preintervention period, we found no evidence that the difference in length of stay was due to increased surveillance for nondiabetics, especially because eligibility criteria depended on phlebotomy glucose values, which were uniformly tested in all inpatients. Also, effects on length of stay were actually stronger when limited to patients with known diabetes. Finally, we controlled for several predictors of length of stay, although we still cannot exclude the possibility of unmeasured confounding between groups.

Since ADA and ACE issued guidelines for inpatient management of diabetes and hyperglycemia, many institutions have developed subcutaneous insulin algorithms, educational curricula, and/or order sets to increase compliance with these guidelines and improve glycemic control. Some of these efforts have been studied and some have been successful in their efforts.13, 14, 2023 Unfortunately, most of these programs have not rigorously assessed their impact on process and outcomes, and the most effective studies published to date have involved interventions much more intensive than those described here. For example, Rush University's intervention was associated with a 50 mg/dL decrease in mean blood glucose but involved an endocrinologist rounding twice daily with house officers for 2 weeks at a time.13 At Northwestern University, a diabetes management service run by nurse practitioners was established, and the focus was on the conversion from intravenous to subcutaneous insulin regimens.14 The RABBIT 2 study that demonstrated the benefits of a basal‐bolus insulin regimen used daily rounding with an endocrinologist.12 More modestly, a program in Pitt County Memorial Hospital in Greenville, NC, relied mostly on diabetes nurse case managers, a strategy which reduced hospital‐wide mean glucose levels as well as LOS, although the greatest improvements in glycemic control were seen in the ICU.19 Our findings are much more consistent with those from University of California San Diego, as yet unpublished, which also used an algorithm, computerized order set, education, as well as continuous quality improvement methods to achieve its aims.22

Our study has several limitations, including being conducted on 1 general medicine service at 1 academic medical center. Moreover, this service, using a physician assistant/hospitalist model, a closed geographic unit, and fairly generous staffing ratio, is likely different from those in many settings and may limit the generalizability of our findings. However, this model allowed us to conduct the study in a laboratory relatively untouched by other cointerventions. Furthermore, the use of PAs in this way may become more common as both academic and community hospitals rely more on mid‐level providers. Our study had a relatively low percentage of patients without a known diagnosis of diabetes compared with other studies, again potentially but not necessarily limiting generalizability. This finding has been shown in other studies at our institution24 and may be due to the high rate of screening for diabetes in the community. Another limitation is that this was a nonrandomized, before‐after trial. However, all subjects were prospectively enrolled to improve comparability, and we performed rigorous adjustment for multiple potential confounding factors. Also, this study had limited statistical power to detect differences in hypoglycemia rates. The preintervention arm was smaller than planned due to fewer diabetic patients than expected on the service and a higher number of exclusions; we prolonged the postintervention period to achieve the desired sample size for that arm of the study.

Our study also has several strengths, including electronic capture of many processes of care and a methodology to operationalize them into measures of protocol adherence. Our metrics of glycemic control were rigorously designed and based on a national task force on inpatient glycemic control sponsored by the Society of Hospital Medicine, with representation from the ADA and AACE.25

Potential future improvements to this intervention include modifications to the daily adjustment algorithm to improve its usability and ability to improve glucose control. Another is the use of high‐reliability methods to improve order set use and daily insulin adjustment, including alerts within the CPOE system and nurse empowerment to contact medical teams if glucose levels are out of range (eg, if greater than 180 mg/dL, not just if greater than 350 or 400 mg/dL). Future research directions include multicenter, randomized controlled trials of these types of interventions and an analysis of more distal patient outcomes including total healthcare utilization, infection rates, end‐organ damage, and mortality.

In conclusion, we found a relationship between a relatively low‐cost quality improvement intervention and improved glycemic control in the non‐ICU general medical setting. Such a finding suggests the benefits of the algorithm itself to improve glucose control and of our implementation strategy. Other institutions may find this intervention a useful starting point for their own quality improvement efforts. Both the algorithm and implementation strategy are deserving of further improvements and future study.

Acknowledgements

We thank Paul Szumita, Karen Fiumara, Jennifer Trujillo, and the other members of the BWH Diabetes Pharmacy and Therapeutics Subcommittee for their help designing and implementing the intervention; Aubre McClendon, Nicole Auclair, Emily Dattwyler, Mariya Fiman, and Alison Pietras for valuable research assistance; Deborah Williams for data analysis; Amy Bloom for project support; and Stuart Lipsitz for biostatistical expertise.

APPENDIX

INPATIENT DIABETES MANAGEMENT PROTOCOL

Management of Diabetes and Hyperglycemia in Hospitalized Non‐ICU Patients

Rationale

Increasing data show a strong association between hyperglycemia and adverse inpatient outcomes. The American Diabetes Association and the American College of Clinical Endocrinology recommend all glucose levels be below 180 mg/dL in non‐ICU patients. Because hospitalizations are unstable situations, even patients who are well controlled on oral agents as outpatients are usually best managed with insulin.

Insulin may be safely administered even to patients without previously diagnosed diabetes. As long as the prescribed doses are below what is normally produced by the pancreas, the patient will not become hypoglycemic. If the glucose level drops, endogenous insulin secretion will reduce to compensate.

Total insulin requirements in insulin‐sensitive patients (eg, type 1 diabetes mellitus) is 0.50.7/units/kg/day. Insulin requirements in insulin‐resistant type 2 diabetic patients may vary greatly, and can exceed 12 units/kg/day. A conservative estimate for initial insulin therapy in any patient with diabetes is to start with the type 1 diabetes mellitus dose, 0.50.7 units/kg/day.

Overview

Effective inpatient insulin regimens typically include 3 components:

  • Basal insulin (eg, scheduled NPH or insulin glargine [Lantus]), which is used to manage fasting and premeal hyperglycemia.

  • Nutritional or prandial insulin (eg, scheduled regular insulin, insulin lispro [Humalog] or insulin aspart [Novolog]) which controls hyperglycemia from nutritional (eg, discrete meals, TPN, IV dextrose) sources.

  • Supplemental or correctional insulin (eg, regular insulin, insulin lispro, or insulin aspart), which is used in addition to scheduled insulin to meet unexpected basal hyperglycemia that is not covered by the scheduled insulin.

 

Sample Orders (Not for Patients with Uncontrolled Type 1 Diabetes, DKA, Hyperglycemic Hyperosmolar State, or Other Absolute Need for IV Insulin)

 

  • Check (fingerstick) capillary blood glucose qAC, qHS.

  • NPH insulin subcutaneously (SC) ___ units qAM, ___ units qHS.

  • Insulin aspart SC ___ units pre‐breakfast, ___ units pre‐lunch, ___ units pre‐dinner, hold if NPO or premeal BS <60 mg/dL; give 015 minutes before meals.

  • Insulin aspart SC sliding scale (see Table 6) qAC, in addition to standing nutritional insulin, 015 minutes before meals.

  • For BS <60 mg/dL:

     

    • If patient can take PO

       

      • Give 15 g of fast acting carbohydrate (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets).

      • Repeat finger capillary glucose every 15 (q15) minutes and repeat above (5.a.i.) if BG <60 mg/dL.

      • When BG >60 mg/dL, give snack or meal in a half‐hour.

      • If patient cannot take PO

         

        • Give 25 mL of 50% dextrose (D50) as an IV push.;

        • Repeat finger capillary glucose q15 minutes and repeat above (5.b.i.) if BG <80 mg/dL.

         

Guidelines

 

  • Stop oral diabetes agents in most patients (see Table 7 for list of contraindications and precautions).

  • Check bedside blood glucose (BBG or fingerstick) qAC and qHS (or at 0600 hours, 1200 hours, 1800 hours, and 2400 hours if no discrete meals).

  • Estimate total daily insulin requirement:

     

    • For most patients, conservative estimate is 0.50.7 units/kg/day, but may be much higher.

    • Reasons for lower end of the range: renal insufficiency, small size, insulin sensitive (eg, type 1), recent hypoglycemia, decreasing doses of steroids, older age.

    • Reasons for higher end of the range: obese, initiation or increasing doses of steroids, marked hyperglycemia.

    • Start basal insulin if any premeal BG >140 mg/dL and no recent glucose <60 mg/dL off insulin (Table 5).

    • Start nutritional or prandial insulinhold if nutrition is stopped/held or premeal BS <60 (Table 5).

    • Start supplemental/correctional insulin in addition to nutritional (prandial) insulin (Table 6):

       

      • Discrete meals: Insulin aspart qAC (with nutritional insulin). 0

      • No discrete meals: Regular insulin q6h.

      • On a daily basis, adjust scheduled insulin based on previous days' blood sugars:

         

        • Add up total insulin given the previous day, including scheduled and supplemental insulin, to determine new total daily insulin requirement.

        • Adjust total daily insulin requirement based on clinical considerations (eg, give more if marked hyperglycemia, eating more, improving renal function, increasing steroids; give less if eating less, worsening renal function, tapering steroids, recovering from severe illness).

        • Give 50% of requirement as basal and 50% as nutritional, as above (may need proportionately less nutritional insulin if appetite poor or unknown).

        • Adjust sliding scale if needed based on total scheduled insulin dose (see step 6, above).

        • For BG <60 mg/dL:

           

          • If patient can take PO, give 15 g of fast acting carbohydrate.

          • (4 oz fruit juice/nondiet soda, 8 oz nonfat milk, or 34 glucose tablets; not juice plus sugar).

          • Repeat finger capillary glucose q15 minutes and repeat above if BG <60.

          • When BG >60, give snack or meal in half an hour.

          • If patient cannot take PO, give 25 mL of D50 as IV push.

          • Check finger capillary glucose q15 minutes and repeat above if BG <80.

          • Discharge orders:

             

            • Patient should be discharged home on a medication regimen that was similar to the admission regimen (ie, the regimen prescribed by their PCP). Exceptions include

               

              • The patient has a contraindication to an admission medication.

              • There is evidence of severe hyperglycemia (eg, very high A1C) or hypoglycemia on admission regimen.

              • If a patient is admitted with no insulin, and requires insulin to be continued as an outpatient (eg, newly‐diagnosed type 1 diabetes, A1C very high, and contraindication to or on maximum oral regimen), limit discharge insulin regimen to no more than 1 injection per day (eg, hs NPH; an exception to this is for type 1 diabetic patients, who are optimally treated with 34 injections/day). Make sure the patient has prompt follow‐up with their primary care provider (PCP).

              • Avoid discharging home on sliding scale.

              • If a patient is going to require insulin injections and self‐monitoring blood glucose as an outpatient, make sure they are instructed about how to perform these.

              • Indications for calling an endocrine consult:

                 

                • Labile blood sugars.

                • Prolonged periods of NPO, eg, for procedures, especially in patients with type 1 diabetes

                • Marked hyperglycemia despite following this guideline.

                • Question of type 1 versus type 2 versus other type of diabetes. 0

                 

                Basil Insulin Guidelines
                Home Insulin RegimenStarting Dose of Basal InsulinConsiderations
                • NOTE: Patients with T1DM require basal insulin at all times! Basal never should be held!

                • Abbreviations: NPO, nothing by mouth.

                On basal (eg, NPH or glargine) insulin at homePatient's home dose of NPH or glargineIf NPO, consider starting half of NPH or glargine home dose, unless hyperglycemic at home.
                Not on basal (eg, NPH or glargine) insulin at homeNPH 50% of total daily insulin requirement, given qHS or split qAM/qHS (maximum starting dose 20 units/day)Same dose if patient has previously diagnosed or undiagnosed diabetes
                Nutritional Insulin Guidelines
                Type of NutritionCommon Nutritional RegimensSample Starting Doses
                • Abbreviation: qAM, every morning; qHS, at bed time.

                • If receiving cycled tube feeds at night, give nutritional NPH qHS only.

                Discrete mealsAspart given 015 minutes before mealsHome dose, if known or
                50% of total insulin requirement, split over 3 meals, may need less if poor or unknown appetite
                Continuous tube feeding,* IV dextroseNPH qHS or qAM/qHS50% of total insulin requirement (in addition to basal dose), may need less if not at goal caloric intake
                Glargine given every day (qd), anytime
                Regular every 6 hours (q6h)
                Sample Supplemental/Correctional Insulin Scales
                Blood GlucoseScheduled Insulin < 40 Units/DayScheduled Insulin of 4080 Units/DayScheduled Insulin > 80 Units/DayIndividualized
                • NOTE: Avoid supplemental insulin qHS unless patient is very hyperglycemic and obese.

                1501991 unit1 unit2 units____ units
                2002492 units3 units4 units____ units
                2502993 units5 units7 units____ units
                3003494 units7 units10 units____ units
                >3495 units + call HO8 units + call HO12 units + call HO___ units + call HO
                Notes on Oral Agents
                AgentsConsiderationsMetabolism
                Sulfonylureas/secretagogues: glyburide, glipizide, glimeperide (Amaryl); repaglinide (Prandin); nateglinide (Starlix)Risk for hypoglycemiaMetabolized in liver; Glyburide metabolized to active metabolites; 50% renally eliminated
                MetforminContraindicated in heart failure and renal dysfunction (creatinine [Cr] >1.5 mg/dL in men and 1.4 mg/dL in women)Eliminated renally
                Should be held at time of iodinated contrast studies. (May be restarted after normal postcontrast renal function is confirmed)
                Adverse effects include diarrhea, nausea, and anorexia
                Thiazolidinediones: pioglitazone (Actos), rosiglitazone (Avandia)Contraindicated in class III and IV heart failureMetabolized in liver
                Use with caution in patients with edema
                Adverse effects include increased intravascular volume
                Slow onset of action
                Avoid in hepatic dysfunction
                Glucosidease inhibitors: acarbose (Precose), miglitol (Glycet)Gastrointestinal intoleranceAcarbose eliminated in gut and renally
References
  1. Wexler DJ,Meigs JB,Cagliero E,Nathan DM,Grant RW.Prevalence of hyper‐ and hypoglycemia among inpatients with diabetes: a national survey of 44 U.S. hospitals.Diabetes Care.2007;30:367369.
  2. Umpierrez GE,Isaacs SD,Bazargan N,You X,Thaler LM,Kitabchi AE.Hyperglycemia: an independent marker of in‐hospital mortality in patients with undiagnosed diabetes.J Clin Endocrinol Metab.2002;87:978982.
  3. Baker EH,Janaway CH,Philips BJ, et al.Hyperglycaemia is associated with poor outcomes in patients admitted to hospital with acute exacerbations of chronic obstructive pulmonary disease.Thorax.2006;61:284289.
  4. Capes SE,Hunt D,Malmberg K,Pathak P,Gerstein HC.Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview.Stroke.2001;32:24262432.
  5. Cheung NW,Napier B,Zaccaria C,Fletcher JP.Hyperglycemia is associated with adverse outcomes in patients receiving total parenteral nutrition.Diabetes Care.2005;28:23672371.
  6. Clement S,Braithwaite SS,Magee MF, et al.Management of diabetes and hyperglycemia in hospitals.Diabetes Care.2004;27:553597.
  7. McAlister FA,Majumdar SR,Blitz S,Rowe BH,Romney J,Marrie TJ.The relation between hyperglycemia and outcomes in 2471 patients admitted to the hospital with community‐acquired pneumonia.Diabetes Care.2005;28:810815.
  8. Van den Berghe G,Wilmer A,Hermans G, et al.Intensive insulin therapy in the medical ICU.N Engl J Med.2006;354:449461.
  9. van den Berghe G,Wouters P,Weekers F, et al.Intensive insulin therapy in the critically ill patients.N Engl J Med.2001;345:13591367.
  10. Standards of medical care in diabetes, 2007.Diabetes Care.2007;30(Suppl 1):S4S41.
  11. American College of Endocrinology and American Diabetes Association Consensus statement on inpatient diabetes and glycemic control: a call to action.Diabetes Care.2006;29:19551962.
  12. Umpierrez GE,Smiley D,Zisman A, et al.Randomized study of basal‐bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial).Diabetes Care.2007;30:21812186.
  13. Baldwin D,Villanueva G,McNutt R,Bhatnagar S.Eliminating inpatient sliding‐scale insulin: a reeducation project with medical house staff.Diabetes Care.2005;28:10081011.
  14. DeSantis AJ,Schmeltz LR,Schmidt K, et al.Inpatient management of hyperglycemia: the Northwestern experience.Endocr Pract.2006;12:491505.
  15. Trujillo JM,Barsky EE,Greenwood BC, et al.Improving glycemic control in medical inpatients: a pilot study.J Hosp Med.2008;3:5563.
  16. Deyo RA,Cherkin DC,Ciol MA.Adapting a clinical comorbidity index for use with ICD‐9‐CM administrative databases.J Clin Epidemiol.1992;45:613619.
  17. Goldberg PA,Bozzo JE,Thomas PG, et al.“Glucometrics”—assessing the quality of inpatient glucose management.Diabetes Technol Ther.2006;8:560569.
  18. Garg R,Bhutani H,Alyea E,Pendergrass M.Hyperglycemia and length of stay in patients hospitalized for bone marrow transplantation.Diabetes Care.2007;30:993994.
  19. Newton CA,Young S.Financial implications of glycemic control: results of an inpatient diabetes management program.Endocr Pract.2006;12(Suppl 3):4348.
  20. Elinav H,Wolf Z,Szalat A, et al.In‐hospital treatment of hyperglycemia: effects of intensified subcutaneous insulin treatment.Curr Med Res Opin.2007;23:757765.
  21. Levetan CS,Salas JR,Wilets IF,Zumoff B.Impact of endocrine and diabetes team consultation on hospital length of stay for patients with diabetes.Am J Med.1995;99:2228.
  22. Maynard GA,Lee J,Fink E,Renvall M.Effect of a standardized insulin order set and an insulin management algorithm on inpatient glycemic control and hypoglycemia. Society of Hospital Medicine Annual Meeting, 2007; Dallas, TX;2007.
  23. Sampson MJ,Crowle T,Dhatariya K, et al.Trends in bed occupancy for inpatients with diabetes before and after the introduction of a diabetes inpatient specialist nurse service.Diabet Med.2006;23:10081015.
  24. Schnipper JL,Barsky EE,Shaykevich S,Fitzmaurice G,Pendergrass ML.Inpatient management of diabetes and hyperglycemia among general medicine patients at a large teaching hospital.J Hosp Med.2006;1:145150.
  25. Maynard GA,Wesorick DH,Magee MF, et al. Improving glycemic control, preventing hypoglycemia, and optimizing care of the inpatient with hyperglycemia and diabetes, 2006. Available at:http://www.hospitalmedicine.org/ResourceRoomRedesign/html/GC_Imp_Guide.cfm. Accessed October 2008.
References
  1. Wexler DJ,Meigs JB,Cagliero E,Nathan DM,Grant RW.Prevalence of hyper‐ and hypoglycemia among inpatients with diabetes: a national survey of 44 U.S. hospitals.Diabetes Care.2007;30:367369.
  2. Umpierrez GE,Isaacs SD,Bazargan N,You X,Thaler LM,Kitabchi AE.Hyperglycemia: an independent marker of in‐hospital mortality in patients with undiagnosed diabetes.J Clin Endocrinol Metab.2002;87:978982.
  3. Baker EH,Janaway CH,Philips BJ, et al.Hyperglycaemia is associated with poor outcomes in patients admitted to hospital with acute exacerbations of chronic obstructive pulmonary disease.Thorax.2006;61:284289.
  4. Capes SE,Hunt D,Malmberg K,Pathak P,Gerstein HC.Stress hyperglycemia and prognosis of stroke in nondiabetic and diabetic patients: a systematic overview.Stroke.2001;32:24262432.
  5. Cheung NW,Napier B,Zaccaria C,Fletcher JP.Hyperglycemia is associated with adverse outcomes in patients receiving total parenteral nutrition.Diabetes Care.2005;28:23672371.
  6. Clement S,Braithwaite SS,Magee MF, et al.Management of diabetes and hyperglycemia in hospitals.Diabetes Care.2004;27:553597.
  7. McAlister FA,Majumdar SR,Blitz S,Rowe BH,Romney J,Marrie TJ.The relation between hyperglycemia and outcomes in 2471 patients admitted to the hospital with community‐acquired pneumonia.Diabetes Care.2005;28:810815.
  8. Van den Berghe G,Wilmer A,Hermans G, et al.Intensive insulin therapy in the medical ICU.N Engl J Med.2006;354:449461.
  9. van den Berghe G,Wouters P,Weekers F, et al.Intensive insulin therapy in the critically ill patients.N Engl J Med.2001;345:13591367.
  10. Standards of medical care in diabetes, 2007.Diabetes Care.2007;30(Suppl 1):S4S41.
  11. American College of Endocrinology and American Diabetes Association Consensus statement on inpatient diabetes and glycemic control: a call to action.Diabetes Care.2006;29:19551962.
  12. Umpierrez GE,Smiley D,Zisman A, et al.Randomized study of basal‐bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial).Diabetes Care.2007;30:21812186.
  13. Baldwin D,Villanueva G,McNutt R,Bhatnagar S.Eliminating inpatient sliding‐scale insulin: a reeducation project with medical house staff.Diabetes Care.2005;28:10081011.
  14. DeSantis AJ,Schmeltz LR,Schmidt K, et al.Inpatient management of hyperglycemia: the Northwestern experience.Endocr Pract.2006;12:491505.
  15. Trujillo JM,Barsky EE,Greenwood BC, et al.Improving glycemic control in medical inpatients: a pilot study.J Hosp Med.2008;3:5563.
  16. Deyo RA,Cherkin DC,Ciol MA.Adapting a clinical comorbidity index for use with ICD‐9‐CM administrative databases.J Clin Epidemiol.1992;45:613619.
  17. Goldberg PA,Bozzo JE,Thomas PG, et al.“Glucometrics”—assessing the quality of inpatient glucose management.Diabetes Technol Ther.2006;8:560569.
  18. Garg R,Bhutani H,Alyea E,Pendergrass M.Hyperglycemia and length of stay in patients hospitalized for bone marrow transplantation.Diabetes Care.2007;30:993994.
  19. Newton CA,Young S.Financial implications of glycemic control: results of an inpatient diabetes management program.Endocr Pract.2006;12(Suppl 3):4348.
  20. Elinav H,Wolf Z,Szalat A, et al.In‐hospital treatment of hyperglycemia: effects of intensified subcutaneous insulin treatment.Curr Med Res Opin.2007;23:757765.
  21. Levetan CS,Salas JR,Wilets IF,Zumoff B.Impact of endocrine and diabetes team consultation on hospital length of stay for patients with diabetes.Am J Med.1995;99:2228.
  22. Maynard GA,Lee J,Fink E,Renvall M.Effect of a standardized insulin order set and an insulin management algorithm on inpatient glycemic control and hypoglycemia. Society of Hospital Medicine Annual Meeting, 2007; Dallas, TX;2007.
  23. Sampson MJ,Crowle T,Dhatariya K, et al.Trends in bed occupancy for inpatients with diabetes before and after the introduction of a diabetes inpatient specialist nurse service.Diabet Med.2006;23:10081015.
  24. Schnipper JL,Barsky EE,Shaykevich S,Fitzmaurice G,Pendergrass ML.Inpatient management of diabetes and hyperglycemia among general medicine patients at a large teaching hospital.J Hosp Med.2006;1:145150.
  25. Maynard GA,Wesorick DH,Magee MF, et al. Improving glycemic control, preventing hypoglycemia, and optimizing care of the inpatient with hyperglycemia and diabetes, 2006. Available at:http://www.hospitalmedicine.org/ResourceRoomRedesign/html/GC_Imp_Guide.cfm. Accessed October 2008.
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Implementation of a physician assistant/hospitalist service in an academic medical center: Impact on efficiency and patient outcomes

Midlevel providers (physician assistants and nurse practitioners) have long been employed by academic medical centers, predominantly on surgical services, or on medical subspecialty services, where they have typically had a limited scope of practice, focused in a narrowly defined area or set of procedures.17 In contrast, there are relatively few reports of experiences deploying midlevel providers to replace house staff on inpatient general medicine services in academic centers,810 and few studies of the effect of midlevel providers on quality and efficiency of care in the academic setting. Despite this, reductions in house officer duty hours as mandated by the Accreditation Council on Graduate Medical Education (ACGME)11 have resulted in academic centers increasingly using midlevel providers to decrease house staff workload on inpatient services.12, 13 In general, midlevel practitioners on general medicine services have been deployed to: (1) care for a population of patients separate from and in parallel with house staff; this population may be narrowly defined (eg, patients with chest pain) or not; (2) assist with the management of patients cared for by house staff by performing certain tasks (eg, scheduling appointments, discharging patients). Even as midlevel providers become more prevalent on academic general medicine services, the best model of care incorporating them into clinical care remains unclear, and few studies have rigorously examined the care provided on services that use them.

We developed an inpatient general medicine service within a large academic medical center staffed by physician assistants and hospitalists to help our residency program meet ACGME duty hour requirements. We hypothesized that by creating a service that is geographically localized and supervised by full‐time hospitalists, by instituting multidisciplinary rounds, and by investing in the professional development of highly‐skilled physician assistants, we could provide care for medically complex, acutely ill general medicine inpatients with similar quality and efficiency as compared to house staff teams. We report our experience during the first year of implementing the service, and compare quality and efficiency of care on this service with that of our traditional house staff services. We also evaluate the effects of this service on patient satisfaction and self‐reported house staff workload.

PATIENTS AND METHODS

Study Setting

The study was conducted in a 747‐bed urban, academic medical center in the northeastern United States. The hospital's human research committee reviewed and approved the study design. The hospital has accredited residency and fellowship programs in all major specialties. Prior to July 2005, physician assistants were employed only on surgical and medical subspecialty services (ie, bone marrow transplant, interventional cardiology); none were employed on the inpatient general medicine service. There were approximately 44,000 inpatient admissions during the year of the study, with approximately 6500 of these to the general medicine service.

Description of the General Medicine Service

The General Medicine Service consisted of 8 traditional house staff teams, with 1 attending, 1 junior or senior resident, 2 interns, and 1 or 2 medical students. These teams admitted patients on a rotating basis every fourth day. On 4 of these teams, the attending was a hospitalist, with clinical responsibility for the majority of the patients admitted to the team. On the remaining 4 teams, the teaching attending was a primary care physician or medical subspecialist, responsible for the direct care of a small number of the team's patients, with the remainder cared for by private primary care physicians or subspecialists.

Description of the Physician Assistant/Hospitalist Service

The Physician Assistant/Clinician Educator (PACE) service opened in July 2005, and consisted of 15 beds localized to 2 adjacent inpatient pods, staffed by a single cadre of nurses and medically staffed by 1 hospitalist and 2 physician assistants from 7:00 AM to 7:00 PM on weekdays and by 1 hospitalist, 1 physician assistant, and 1 moonlighter (usually a senior medical resident or fellow) from 7:00 AM to 7:00 PM on weekends. A moonlighter, typically a senior resident or medical subspecialty fellow, admitted patients and covered nights on the service from 7:00 PM to 7:00 AM 7 days a week. The daily census goal for the service was 15 patients, limited by the number of available beds on the 2 pods, and the service accepted admissions 24 hours per day, 7 days per week, whenever beds were available. Daily morning rounds occurred at 8:00 AM and included the hospitalist, physician assistants, nurses, a care coordinator, and a pharmacist. The PACE service did not have triage guidelines related to diagnosis, complexity, or acuity, but only accepted patients via the emergency department or via a primary care physician's office, and did not accept patients transferred from outside hospitals or from the intensive care units.

Physician Assistants

All of the physician assistants on the PACE service had prior inpatient medicine experience, ranging from 6 months to 5 years. The physician assistants worked in 3‐day to 6‐day blocks of 12‐hour shifts. Their clinical responsibilities were similar to those of interns at the study hospital, and included taking histories and performing physical examinations, writing notes and orders, reviewing and assimilating data, creating and updating patient signouts, completing discharge summaries, consulting other services as needed, and communicating with nurses and family members.

Many physician assistants also had nonclinical responsibilities, taking on physician‐mentored roles in education, quality improvement, and administration. They were involved in several initiatives: (1) developing a physician assistant curriculum in hospital medicine, (2) presenting at hospital‐wide physician assistant grand rounds, (3) surveying and tracking patient and family satisfaction on the service, (4) reviewing all 72‐hour hospital readmissions, intensive care unit transfers, and deaths on the service, and (5) maintaining the service's compliance with state regulations regarding physician assistant scope of practice and prescribing.

Hospitalists

The 3 hospitalists on the PACE service worked in 7‐day blocks of 12‐hour shifts (7:00 AM to 7:00 PM). They directly supervised the physician assistants and had no competing responsibilities. The hospitalists were all recent graduates of the study hospital's internal medicine residency, with no prior clinical experience beyond residency. All were planning to work on the service for 1 to 2 years before beginning a subspecialty fellowship. In addition to supervising the clinical work of the physician assistants, the hospitalists were responsible for teaching the physician assistants on rounds and in weekly didactic sessions, guided by a curriculum in hospital medicine that focused on the most common general medicine diagnoses seen on the PACE service. The medical director of the PACE service periodically reviewed each physician assistant's clinical experience, skills and knowledge base, and held semiannual feedback sessions.

Study Patients

All general medicine patients admitted to the PACE service from July 1, 2005 to June 30, 2006 comprised the study population. The comparison group consisted of general medicine patients admitted to the 8 house staff general medicine teams; patients transferred from an intensive care unit (ICU) or another facility were excluded in order to match the admission criteria for the PACE service and improve comparability between the 2 study arms.

Data Collection and Study Outcomes

We obtained all patient data from the hospital's administrative databases. We identified patients assigned to the PACE service or to the comparison group based on the admitting service, team, and attending. We obtained patient demographics, insurance, admission source and discharge destination, admission and discharge times, dates, diagnoses, and diagnosis‐related groups (DRGs), as well as dates and times of transfers to other services, including to the intensive care unit. We also obtained the Medicare case‐mix index (CMI, based on DRG weight), and calculated a Charlson score based on billing diagnoses coded in the year prior to the index admission.14 Outcomes included length of stay (LOS) to the nearest hour, in‐hospital mortality, transfers to the intensive care unit, readmissions to the study hospital within 72 hours, 14 days, and 30 days, and total costs as derived from the hospital's cost accounting system (Transition Systems Inc., Boston, MA). Other outcomes included patient satisfaction as measured by responses to the Press‐Ganey survey routinely administered to a randomly selected 70% of recently discharged patients and effect on self‐reported resident work hours.

Statistical Analysis

Patient demographics, clinical characteristics, and study outcomes are presented using proportions, means with standard deviations, and medians with inter‐quartile ranges as appropriate. Unadjusted differences in outcomes between the two services were calculated using univariable regression techniques with service as the independent variable and each outcome as the dependent variable. We used logistic regression for dichotomous outcomes (readmissions, ICU transfers, and inpatient mortality), and linear regression for log‐transformed LOS and log‐transformed total costs of care. To adjust each outcome for potential confounders, we then built multivariable regression models. Each potential confounder was entered into the model one at a time as the independent variable. All variables found to be significant predictors of the outcome at the P < 0.10 level were then retained in the final model along with service as the predictor of interest. We used general estimating equations in all multivariable models to adjust for clustering of patients by attending physician. For logistic regression models, the effect size is presented as an odds ratio (OR); for log‐transformed linear regression models, the effect size is presented as the percent difference between groups. We also performed 2 subgroup analyses, limited to (1) the patients with the 10 most common discharge DRGs, and (2) patients admitted between the hours of 7:00 AM and 7:00 PM to remove the effects of moonlighters performing the initial admission. Except as noted above, 2‐sided P values < 0.05 were considered significant. SAS 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

Patient Demographics

Table 1 shows patient demographics and clinical characteristics of the PACE service and the comparison group. Patients in the comparison group were slightly older and tended to have slightly higher CMI and Charlson scores. Patients on the PACE service were more likely to be admitted at night (10:00 PM to 7:00 AM; 43.8% versus 30.3%; P < 0.0001). There were no significant differences in sex, race, insurance, or percentage of patients discharged to home. The 10 most common DRGs in the comparison group accounted for 37.0% of discharges, and these same DRGs accounted for 37.5% of discharges on the PACE service (Table 2).

Patient Demographic and Clinical Characteristics
CharacteristicPACE Service (n = 992)House Staff Services (n = 4,202)P value
  • Numbers are percent of patients except where noted.

Age (years)   
184419.118.2 
456435.531.90.04
65+45.549.9 
Sex (% female)57.760.0NS
Race/ethnicity   
White57.359.3 
Black24.023.5NS
Hispanic14.113.3 
Other4.63.9 
Insurance   
Medicare41.943.8 
Commercial34.935.9 
Medicaid14.411.7NS
Free care4.53.9 
Self pay1.10.8 
Median income by zip code of residence, USD (IQR)45,517 (32,49362,932)45,517 (35,88963,275)NS
Case‐mix index, median (IQR)1.1 (0.81.5)1.2 (0.91.8)0.001
Charlson score   
027.224.9 
122.621.10.02
216.216.5 
3+34.037.6 
Admissions between 10:00 PM and 7:00 AM43.830.3<0.0001
Discharged to home81.180.5NS
Distribution of Top 10 Discharge Diagnosis Related Groups
Diagnosis‐Related Group at DischargePACE Service (n = 992)*House Staff Services (n = 4,202)*
  • Percent of all discharges by service.

Chest pain5.46.4
Esophagitis, gastroenteritis, and miscellaneous digestive disorders4.54.4
Heart failure and shock3.44.6
Simple pneumonia and pleurisy2.74.4
Kidney and urinary tract infections4.73.2
Chronic obstructive pulmonary disease4.03.3
Renal failure2.73.5
Gastrointestinal hemorrhage3.72.7
Nutritional and miscellaneous metabolic disorders3.32.4
Disorders of the pancreas except malignancy3.12.1
Cumulative percent37.537.0

Efficiency and Quality of Care

Table 3 compares the performance of the PACE service and the comparison group on several efficiency and quality measures. Unadjusted LOS was not significantly different, and adjusted LOS was slightly but not statistically significantly higher on the study service (adjusted LOS 5.0% higher; 95% confidence interval [CI], 0.4% to +10%). Unadjusted and adjusted total costs of care were marginally lower on the study service (adjusted total cost of care 3.9% lower; 95% CI, 7.5% to 0.3%).

Efficiency and Quality Measures for the PACE Service and House Staff Services
 PACE ServiceHouse Staff ServicesUnadjusted % Difference (95%CI)Adjusted % Difference (95%CI)*
 PACE ServiceHouse Staff ServicesUnadjusted OR (95% CI)Adjusted OR (95% CI)
  • All adjusted models adjusted for clustering by attending physician.

  • Adjusted for age, race, Charlson score, time of admission, insurer, and Case Mix Index (CMI).

  • P ≪ 0.001.

  • P < 0.05.

  • Adjusted for age, sex, race, Charlson score, time of admission, insurer, and CMI, and log of median income by zip code.

  • |Adjusted for race, Charlson score, insurer, CMI, and discharge to home or skilled nursing facility.

  • Adjusted for age, sex, race, Charlson score, CMI, time of admission, and discharge to home or skilled nursing facility.

  • Adjusted for sex, race, Charlson score, CMI, and log of median income by zip code.

Efficiency measure    
Length of stay, days, median (IQR)2.6 (1.6, 4.4)2.6 (1.4, 4.6)+0.1% (5.6% to +6.1%)+5.0% (0.4% to +10.0%)
Total costs, USD, median (IQR)4,536 (2,848, 7,201)4,749 (3,046, 8,161)9.1% (14.0% to 3.8%)3.9% (7.5% to 0.3%)
Quality measure    
72‐hour readmissions/100 discharges0.81.30.6 (0.31.3)0.7 (0.21.8)
14‐day readmissions/100 discharges5.45.41.0 (0.71.4)1.1 (0.81.4)
30‐day readmissions/100 discharges8.08.11.0 (0.81.3)1.1 (0.91.3)
ICU transfers/100 discharges2.02.30.9 (0.51.4)1.4 (0.82.4)#
Inpatient mortality/100 discharges0.71.20.6 (0.31.3)0.8 (0.31.8)**

We found no differences between the PACE service and comparison group in unadjusted rates of hospital readmissions within 72 hours, 14 days, and 30 days, transfer to the intensive care units, or inpatient mortality (Table 3). The associated ORs for each outcome were similar after adjusting for patient demographics and clinical characteristics including severity of illness, as well as for clustering by attending physician.

Subgroup Analyses

When the analysis was limited to the subset of patients with the 10 most common discharge DRGs, the difference in adjusted total cost of care was similar but lost statistical significance (4.0% lower on PACE service; 95% CI, 11.0% to +3.3%). In this subgroup, LOS, readmission rates, and ICU transfer rates were not different. ORs for mortality could not be calculated because there were no deaths in this subgroup on the PACE service (data not shown). When analysis was limited to daytime admissions (to remove any potential effect of admitting by a moonlighter), the difference in total cost of care was attenuated and lost statistical significance (0.2% lower on PACE service; 95%CI, 5.9% to +5.5%). No differences were seen in LOS, mortality, and ICU transfers (data not shown). However, 14‐day readmissions (but not 72‐hour or 30‐day readmissions) were lower on the PACE service (OR, 0.49; 95% CI, 0.25‐0.93).

Patient Satisfaction

Patients were similarly satisfied with their care on the PACE service and on the house staff services. In specific areas and globally, percentages of patients satisfied with their physicians and with the discharge process were not different, as measured by the Press‐Ganey survey (Press‐Ganey Associates, South Bend, IN; Figures 1 and 2). The survey distinguishes between attendings and residents, but not physician assistants; therefore, Figure 1 only includes responses to the attending questions. Given the sampling procedure of the Press‐Ganey survey, exact response rates cannot be calculated, but Press‐Ganey reports a response rate of about 40% for the English survey and about 20% for the Spanish survey.

Figure 1
Press‐Ganey physician scores (% satisfied or very satisfied). P = NS for all comparisons.
Figure 2
Press‐Ganey discharge scores (% satisfied or very satisfied), P = NS for all comparisons.

Resident Duty Hours

Comparing the same month 1 year prior to implementation of the PACE service, mean self‐reported resident duty hours on the general medicine service were unchanged; however, self‐reported data were incomplete, and multiple changes took place in the residency program during the study period. For example, implementation of the PACE service allowed for the dissolution of one full house staff general medicine team and redistribution of these house staff to night float positions and an expanded medical intensive care unit.

Costs of Implementation

The costs associated with implementing the PACE service included physician and physician assistant salaries (2.5 full‐time physicians, 5 full‐time physician assistants, plus fringe) and night coverage by resident and fellow moonlighters (without fringe, and estimated at 50% effort given other moonlighter coverage responsibilities on subspecialty services). We estimated these costs at $257.50/patient‐day ($115/patient‐day for attending physician compensation, $110/patient‐day for physician assistant compensation, and $32.50/patient‐day for moonlighting coverage).

DISCUSSION

As academic centers struggle with developing a workforce to provide patient care no longer provided by residents, questions about the ideal structure of nonhouse staff inpatient services abound. Although solutions to this problem will be determined to some extent by local factors such as institutional culture and resources, some lessons learned in developing such services will be more widely applicable. We found that by implementing a geographically localized, physician assistant‐staffed hospitalist service, we were able to provide care of similar quality and efficiency to that of traditional house staff services, despite inexperienced hospitalists staffing the service and a medical residency program commonly recognized as one of the best in the country. Adjusted total costs were slightly lower on the PACE service, but this difference was small and of borderline statistical significance. Likewise, no significant differences were seen in any of several quality measures or in patient satisfaction.

Our findings add to the available evidence supporting the use of physician assistants on academic general medicine services, and are germane to academic centers facing reductions in house staff availability and seeking alternative models of care for inpatients. Several specific characteristics of the PACE service and the implications of these should be considered:

  • The service accepted all patients, regardless of diagnosis, acuity, or complexity of illness. This was unlike many previously described nonhouse staff services which were more limited in scope, and allowed more flexibility with patient flow. However, in the end, patients on the PACE service did have a modestly lower case mix index and Charlson score, suggesting that, despite a lack of triage guidelines, there was some bias in the triage of admissions, possibly due to a perception that physician assistants should take care of lower complexity patients. If it is desirable to have a similar distribution of higher complexity patients across house staff and nonhouse staff services, extra efforts may be necessary to overcome this perception.

  • The service was geographically regionalized. Geographic regionalization offered many important advantages, especially with regards to communication among staff, nursing, and consultants, and allowed for multidisciplinary rounds. However, it is possible that the modest, but not statistically significant, trend toward an increased LOS seen on the PACE service might be a reflection of geographic admitting (less incentive to discharge since discharging a patient means taking a new admission).

  • The education and professional development of the physician assistants was a priority. Physician assistants had considerable autonomy and responsibility, and rather than being assigned only lower level administrative tasks, performed all aspects of patient care. They also received regular teaching from the hospitalists, attended house staff teaching conferences, and developed nonclinical roles in education and quality improvement. The higher standards expected of the physician assistants were quite possibly a factor in the quality of care delivered, and almost certainly contributed to physician assistant satisfaction and retention.

 

Our findings contrast with those of Myers et al.,9 who found that a nonteaching service staffed by hospitalists and nurse practitioners had a significantly lower median LOS and hospital charges compared to similar patients on resident‐based services. However, unlike ours, their service cared for a select patient population, and only accepted patients with chest pain at low risk for acute coronary syndrome. Van Rhee et al.10 found that physician assistants on a general medicine service used fewer resources for patients with pneumonia, stroke, and congestive heart failure than resident physicians, and did not exceed the resources used by residents in other diagnoses. The authors did not find a difference in LOS, but did find a significantly higher mortality among patients with pneumonia cared for by physician assistants.

Several limitations should be noted. First, the study was a retrospective analysis of administrative data rather than a randomized trial, and although we employed a standard approach to adjust for a wide range of patient characteristics including severity of illness, there may have been undetected differences in the patient populations studied that may have confounded our results. Second, resident moonlighters admitted patients to the PACE service and, at other times, to the house staff services, and this may have diluted any differences between the groups. However, when we limited our analysis to the subgroup of patients admitted during the day, similar results were obtained, with the exception that the PACE service had a lower rate of 14‐day readmissions, an unexpected finding deserving of further study. Third, the study was conducted in a single academic institution and our findings may not be generalizable to others with different needs and resources; indeed, the costs associated with implementing such a service may be prohibitive for some institutions. Fourth, because of simultaneous changes that were taking place in our residency program, we are unable to accurately assess the impact of the PACE service on resident duty hours. However, resident duty hours did not increase over this time period on the general medicine service, and implementation of the service allowed for redistribution of house staff to other services and positions. Fifth, patient satisfaction data were obtained from responses to the mailed Press‐Ganey survey, to which there is a relatively low response rate. Also, we did not survey providers regarding their satisfaction with the service during the study period. Sixth, the study had limited power to detect clinically important differences in mortality and ICU transfers. Finally, this study is unable to compare this particular model of incorporating midlevel providers into general medical services with other models, only with traditional house staff services.

Future research should focus on determining the most effective and efficient ways to incorporate midlevel providers on academic general medicine services. One important question from the standpoint of house staff training is whether such services should be separate but equal, or should house staff gain experience during residency working with midlevel providers, since they are likely to encounter them in the future whether they stay in academics or not. Different models of care will likely have large implications for the quality and efficiency of patient care, house staff education and satisfaction, and physician assistant job satisfaction and turnover.

In summary, our study demonstrates that a geographically regionalized, multidisciplinary service staffed by hospitalists and physician assistants can be a safe alternative to house staff‐based services for the care of general medicine inpatients in an academic medical center.

References
  1. Heinrich JJ,Fichandler BC,Beinfield M,Frazier W,Krizek TJ,Baue AE.The physician's assistant as resident on surgical service. An example of creative problem solving in surgical manpower.Arch Surg.1980;115:310314.
  2. DeMots H,Coombs B,Murphy E,Palac R.Coronary arteriography performed by a physician assistant.Am J Cardiol.1987;60:784787.
  3. O'Rourke RA.The specialized physician assistant: an alternative to the clinical cardiology trainee.Am J Cardiol.1987;60:901902.
  4. Russell JC,Kaplowe J,Heinrich J.One hospital's successful 20‐year experience with physician assistants in graduate medical education.Acad Med.1999;74:641645.
  5. Thourani VH,Miller JI.Physicians assistants in cardiothoracic surgery: a 30‐year experience in a university center.Ann Thorac Surg.2006;81:195199; discussion 199–200.
  6. Oswanski MF,Sharma OP,Raj SS.Comparative review of use of physician assistants in a level I trauma center.Am Surg.2004;70:272279.
  7. Reines HD,Robinson L,Duggan M,O'Brien BM,Aulenbach K.Integrating midlevel practitioners into a teaching service.Am J Surg.2006;192:119124.
  8. Howie JN,Erickson M.Acute care nurse practitioners: creating and implementing a model of care for an inpatient general medical service.Am J Crit Care.2002;11:448458.
  9. Myers JS,Bellini LM,Rohrbach J,Shofer FS,Hollander JE.Improving resource utilization in a teaching hospital: development of a nonteaching service for chest pain admissions.Acad Med.2006;81:432435.
  10. Van Rhee J,Ritchie J,Eward AM.Resource use by physician assistant services versus teaching services.JAAPA.2002;15:3338.
  11. Philibert I,Friedmann P,Williams WT, for the ACGME Work Group on Resident Duty Hours, Accreditation Council for Graduate Medical Education.New requirements for resident duty hours.JAMA.2002;288:11121114.
  12. Riportella‐Muller R,Libby D,Kindig D.The substitution of physician assistants and nurse practitioners for physician residents in teaching hospitals.Health Aff.1995;14:181191.
  13. Todd BA,Resnick A,Stuhlemmer R,Morris JB,Mullen J.Challenges of the 80‐hour resident work rules: collaboration between surgeons and nonphysician practitioners.Surg Clin North Am.2004;84:15731586.
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Journal of Hospital Medicine - 3(5)
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361-368
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academic medical centers, inpatients, internship and residency, physician assistants, program evaluation, quality of health care
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Midlevel providers (physician assistants and nurse practitioners) have long been employed by academic medical centers, predominantly on surgical services, or on medical subspecialty services, where they have typically had a limited scope of practice, focused in a narrowly defined area or set of procedures.17 In contrast, there are relatively few reports of experiences deploying midlevel providers to replace house staff on inpatient general medicine services in academic centers,810 and few studies of the effect of midlevel providers on quality and efficiency of care in the academic setting. Despite this, reductions in house officer duty hours as mandated by the Accreditation Council on Graduate Medical Education (ACGME)11 have resulted in academic centers increasingly using midlevel providers to decrease house staff workload on inpatient services.12, 13 In general, midlevel practitioners on general medicine services have been deployed to: (1) care for a population of patients separate from and in parallel with house staff; this population may be narrowly defined (eg, patients with chest pain) or not; (2) assist with the management of patients cared for by house staff by performing certain tasks (eg, scheduling appointments, discharging patients). Even as midlevel providers become more prevalent on academic general medicine services, the best model of care incorporating them into clinical care remains unclear, and few studies have rigorously examined the care provided on services that use them.

We developed an inpatient general medicine service within a large academic medical center staffed by physician assistants and hospitalists to help our residency program meet ACGME duty hour requirements. We hypothesized that by creating a service that is geographically localized and supervised by full‐time hospitalists, by instituting multidisciplinary rounds, and by investing in the professional development of highly‐skilled physician assistants, we could provide care for medically complex, acutely ill general medicine inpatients with similar quality and efficiency as compared to house staff teams. We report our experience during the first year of implementing the service, and compare quality and efficiency of care on this service with that of our traditional house staff services. We also evaluate the effects of this service on patient satisfaction and self‐reported house staff workload.

PATIENTS AND METHODS

Study Setting

The study was conducted in a 747‐bed urban, academic medical center in the northeastern United States. The hospital's human research committee reviewed and approved the study design. The hospital has accredited residency and fellowship programs in all major specialties. Prior to July 2005, physician assistants were employed only on surgical and medical subspecialty services (ie, bone marrow transplant, interventional cardiology); none were employed on the inpatient general medicine service. There were approximately 44,000 inpatient admissions during the year of the study, with approximately 6500 of these to the general medicine service.

Description of the General Medicine Service

The General Medicine Service consisted of 8 traditional house staff teams, with 1 attending, 1 junior or senior resident, 2 interns, and 1 or 2 medical students. These teams admitted patients on a rotating basis every fourth day. On 4 of these teams, the attending was a hospitalist, with clinical responsibility for the majority of the patients admitted to the team. On the remaining 4 teams, the teaching attending was a primary care physician or medical subspecialist, responsible for the direct care of a small number of the team's patients, with the remainder cared for by private primary care physicians or subspecialists.

Description of the Physician Assistant/Hospitalist Service

The Physician Assistant/Clinician Educator (PACE) service opened in July 2005, and consisted of 15 beds localized to 2 adjacent inpatient pods, staffed by a single cadre of nurses and medically staffed by 1 hospitalist and 2 physician assistants from 7:00 AM to 7:00 PM on weekdays and by 1 hospitalist, 1 physician assistant, and 1 moonlighter (usually a senior medical resident or fellow) from 7:00 AM to 7:00 PM on weekends. A moonlighter, typically a senior resident or medical subspecialty fellow, admitted patients and covered nights on the service from 7:00 PM to 7:00 AM 7 days a week. The daily census goal for the service was 15 patients, limited by the number of available beds on the 2 pods, and the service accepted admissions 24 hours per day, 7 days per week, whenever beds were available. Daily morning rounds occurred at 8:00 AM and included the hospitalist, physician assistants, nurses, a care coordinator, and a pharmacist. The PACE service did not have triage guidelines related to diagnosis, complexity, or acuity, but only accepted patients via the emergency department or via a primary care physician's office, and did not accept patients transferred from outside hospitals or from the intensive care units.

Physician Assistants

All of the physician assistants on the PACE service had prior inpatient medicine experience, ranging from 6 months to 5 years. The physician assistants worked in 3‐day to 6‐day blocks of 12‐hour shifts. Their clinical responsibilities were similar to those of interns at the study hospital, and included taking histories and performing physical examinations, writing notes and orders, reviewing and assimilating data, creating and updating patient signouts, completing discharge summaries, consulting other services as needed, and communicating with nurses and family members.

Many physician assistants also had nonclinical responsibilities, taking on physician‐mentored roles in education, quality improvement, and administration. They were involved in several initiatives: (1) developing a physician assistant curriculum in hospital medicine, (2) presenting at hospital‐wide physician assistant grand rounds, (3) surveying and tracking patient and family satisfaction on the service, (4) reviewing all 72‐hour hospital readmissions, intensive care unit transfers, and deaths on the service, and (5) maintaining the service's compliance with state regulations regarding physician assistant scope of practice and prescribing.

Hospitalists

The 3 hospitalists on the PACE service worked in 7‐day blocks of 12‐hour shifts (7:00 AM to 7:00 PM). They directly supervised the physician assistants and had no competing responsibilities. The hospitalists were all recent graduates of the study hospital's internal medicine residency, with no prior clinical experience beyond residency. All were planning to work on the service for 1 to 2 years before beginning a subspecialty fellowship. In addition to supervising the clinical work of the physician assistants, the hospitalists were responsible for teaching the physician assistants on rounds and in weekly didactic sessions, guided by a curriculum in hospital medicine that focused on the most common general medicine diagnoses seen on the PACE service. The medical director of the PACE service periodically reviewed each physician assistant's clinical experience, skills and knowledge base, and held semiannual feedback sessions.

Study Patients

All general medicine patients admitted to the PACE service from July 1, 2005 to June 30, 2006 comprised the study population. The comparison group consisted of general medicine patients admitted to the 8 house staff general medicine teams; patients transferred from an intensive care unit (ICU) or another facility were excluded in order to match the admission criteria for the PACE service and improve comparability between the 2 study arms.

Data Collection and Study Outcomes

We obtained all patient data from the hospital's administrative databases. We identified patients assigned to the PACE service or to the comparison group based on the admitting service, team, and attending. We obtained patient demographics, insurance, admission source and discharge destination, admission and discharge times, dates, diagnoses, and diagnosis‐related groups (DRGs), as well as dates and times of transfers to other services, including to the intensive care unit. We also obtained the Medicare case‐mix index (CMI, based on DRG weight), and calculated a Charlson score based on billing diagnoses coded in the year prior to the index admission.14 Outcomes included length of stay (LOS) to the nearest hour, in‐hospital mortality, transfers to the intensive care unit, readmissions to the study hospital within 72 hours, 14 days, and 30 days, and total costs as derived from the hospital's cost accounting system (Transition Systems Inc., Boston, MA). Other outcomes included patient satisfaction as measured by responses to the Press‐Ganey survey routinely administered to a randomly selected 70% of recently discharged patients and effect on self‐reported resident work hours.

Statistical Analysis

Patient demographics, clinical characteristics, and study outcomes are presented using proportions, means with standard deviations, and medians with inter‐quartile ranges as appropriate. Unadjusted differences in outcomes between the two services were calculated using univariable regression techniques with service as the independent variable and each outcome as the dependent variable. We used logistic regression for dichotomous outcomes (readmissions, ICU transfers, and inpatient mortality), and linear regression for log‐transformed LOS and log‐transformed total costs of care. To adjust each outcome for potential confounders, we then built multivariable regression models. Each potential confounder was entered into the model one at a time as the independent variable. All variables found to be significant predictors of the outcome at the P < 0.10 level were then retained in the final model along with service as the predictor of interest. We used general estimating equations in all multivariable models to adjust for clustering of patients by attending physician. For logistic regression models, the effect size is presented as an odds ratio (OR); for log‐transformed linear regression models, the effect size is presented as the percent difference between groups. We also performed 2 subgroup analyses, limited to (1) the patients with the 10 most common discharge DRGs, and (2) patients admitted between the hours of 7:00 AM and 7:00 PM to remove the effects of moonlighters performing the initial admission. Except as noted above, 2‐sided P values < 0.05 were considered significant. SAS 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

Patient Demographics

Table 1 shows patient demographics and clinical characteristics of the PACE service and the comparison group. Patients in the comparison group were slightly older and tended to have slightly higher CMI and Charlson scores. Patients on the PACE service were more likely to be admitted at night (10:00 PM to 7:00 AM; 43.8% versus 30.3%; P < 0.0001). There were no significant differences in sex, race, insurance, or percentage of patients discharged to home. The 10 most common DRGs in the comparison group accounted for 37.0% of discharges, and these same DRGs accounted for 37.5% of discharges on the PACE service (Table 2).

Patient Demographic and Clinical Characteristics
CharacteristicPACE Service (n = 992)House Staff Services (n = 4,202)P value
  • Numbers are percent of patients except where noted.

Age (years)   
184419.118.2 
456435.531.90.04
65+45.549.9 
Sex (% female)57.760.0NS
Race/ethnicity   
White57.359.3 
Black24.023.5NS
Hispanic14.113.3 
Other4.63.9 
Insurance   
Medicare41.943.8 
Commercial34.935.9 
Medicaid14.411.7NS
Free care4.53.9 
Self pay1.10.8 
Median income by zip code of residence, USD (IQR)45,517 (32,49362,932)45,517 (35,88963,275)NS
Case‐mix index, median (IQR)1.1 (0.81.5)1.2 (0.91.8)0.001
Charlson score   
027.224.9 
122.621.10.02
216.216.5 
3+34.037.6 
Admissions between 10:00 PM and 7:00 AM43.830.3<0.0001
Discharged to home81.180.5NS
Distribution of Top 10 Discharge Diagnosis Related Groups
Diagnosis‐Related Group at DischargePACE Service (n = 992)*House Staff Services (n = 4,202)*
  • Percent of all discharges by service.

Chest pain5.46.4
Esophagitis, gastroenteritis, and miscellaneous digestive disorders4.54.4
Heart failure and shock3.44.6
Simple pneumonia and pleurisy2.74.4
Kidney and urinary tract infections4.73.2
Chronic obstructive pulmonary disease4.03.3
Renal failure2.73.5
Gastrointestinal hemorrhage3.72.7
Nutritional and miscellaneous metabolic disorders3.32.4
Disorders of the pancreas except malignancy3.12.1
Cumulative percent37.537.0

Efficiency and Quality of Care

Table 3 compares the performance of the PACE service and the comparison group on several efficiency and quality measures. Unadjusted LOS was not significantly different, and adjusted LOS was slightly but not statistically significantly higher on the study service (adjusted LOS 5.0% higher; 95% confidence interval [CI], 0.4% to +10%). Unadjusted and adjusted total costs of care were marginally lower on the study service (adjusted total cost of care 3.9% lower; 95% CI, 7.5% to 0.3%).

Efficiency and Quality Measures for the PACE Service and House Staff Services
 PACE ServiceHouse Staff ServicesUnadjusted % Difference (95%CI)Adjusted % Difference (95%CI)*
 PACE ServiceHouse Staff ServicesUnadjusted OR (95% CI)Adjusted OR (95% CI)
  • All adjusted models adjusted for clustering by attending physician.

  • Adjusted for age, race, Charlson score, time of admission, insurer, and Case Mix Index (CMI).

  • P ≪ 0.001.

  • P < 0.05.

  • Adjusted for age, sex, race, Charlson score, time of admission, insurer, and CMI, and log of median income by zip code.

  • |Adjusted for race, Charlson score, insurer, CMI, and discharge to home or skilled nursing facility.

  • Adjusted for age, sex, race, Charlson score, CMI, time of admission, and discharge to home or skilled nursing facility.

  • Adjusted for sex, race, Charlson score, CMI, and log of median income by zip code.

Efficiency measure    
Length of stay, days, median (IQR)2.6 (1.6, 4.4)2.6 (1.4, 4.6)+0.1% (5.6% to +6.1%)+5.0% (0.4% to +10.0%)
Total costs, USD, median (IQR)4,536 (2,848, 7,201)4,749 (3,046, 8,161)9.1% (14.0% to 3.8%)3.9% (7.5% to 0.3%)
Quality measure    
72‐hour readmissions/100 discharges0.81.30.6 (0.31.3)0.7 (0.21.8)
14‐day readmissions/100 discharges5.45.41.0 (0.71.4)1.1 (0.81.4)
30‐day readmissions/100 discharges8.08.11.0 (0.81.3)1.1 (0.91.3)
ICU transfers/100 discharges2.02.30.9 (0.51.4)1.4 (0.82.4)#
Inpatient mortality/100 discharges0.71.20.6 (0.31.3)0.8 (0.31.8)**

We found no differences between the PACE service and comparison group in unadjusted rates of hospital readmissions within 72 hours, 14 days, and 30 days, transfer to the intensive care units, or inpatient mortality (Table 3). The associated ORs for each outcome were similar after adjusting for patient demographics and clinical characteristics including severity of illness, as well as for clustering by attending physician.

Subgroup Analyses

When the analysis was limited to the subset of patients with the 10 most common discharge DRGs, the difference in adjusted total cost of care was similar but lost statistical significance (4.0% lower on PACE service; 95% CI, 11.0% to +3.3%). In this subgroup, LOS, readmission rates, and ICU transfer rates were not different. ORs for mortality could not be calculated because there were no deaths in this subgroup on the PACE service (data not shown). When analysis was limited to daytime admissions (to remove any potential effect of admitting by a moonlighter), the difference in total cost of care was attenuated and lost statistical significance (0.2% lower on PACE service; 95%CI, 5.9% to +5.5%). No differences were seen in LOS, mortality, and ICU transfers (data not shown). However, 14‐day readmissions (but not 72‐hour or 30‐day readmissions) were lower on the PACE service (OR, 0.49; 95% CI, 0.25‐0.93).

Patient Satisfaction

Patients were similarly satisfied with their care on the PACE service and on the house staff services. In specific areas and globally, percentages of patients satisfied with their physicians and with the discharge process were not different, as measured by the Press‐Ganey survey (Press‐Ganey Associates, South Bend, IN; Figures 1 and 2). The survey distinguishes between attendings and residents, but not physician assistants; therefore, Figure 1 only includes responses to the attending questions. Given the sampling procedure of the Press‐Ganey survey, exact response rates cannot be calculated, but Press‐Ganey reports a response rate of about 40% for the English survey and about 20% for the Spanish survey.

Figure 1
Press‐Ganey physician scores (% satisfied or very satisfied). P = NS for all comparisons.
Figure 2
Press‐Ganey discharge scores (% satisfied or very satisfied), P = NS for all comparisons.

Resident Duty Hours

Comparing the same month 1 year prior to implementation of the PACE service, mean self‐reported resident duty hours on the general medicine service were unchanged; however, self‐reported data were incomplete, and multiple changes took place in the residency program during the study period. For example, implementation of the PACE service allowed for the dissolution of one full house staff general medicine team and redistribution of these house staff to night float positions and an expanded medical intensive care unit.

Costs of Implementation

The costs associated with implementing the PACE service included physician and physician assistant salaries (2.5 full‐time physicians, 5 full‐time physician assistants, plus fringe) and night coverage by resident and fellow moonlighters (without fringe, and estimated at 50% effort given other moonlighter coverage responsibilities on subspecialty services). We estimated these costs at $257.50/patient‐day ($115/patient‐day for attending physician compensation, $110/patient‐day for physician assistant compensation, and $32.50/patient‐day for moonlighting coverage).

DISCUSSION

As academic centers struggle with developing a workforce to provide patient care no longer provided by residents, questions about the ideal structure of nonhouse staff inpatient services abound. Although solutions to this problem will be determined to some extent by local factors such as institutional culture and resources, some lessons learned in developing such services will be more widely applicable. We found that by implementing a geographically localized, physician assistant‐staffed hospitalist service, we were able to provide care of similar quality and efficiency to that of traditional house staff services, despite inexperienced hospitalists staffing the service and a medical residency program commonly recognized as one of the best in the country. Adjusted total costs were slightly lower on the PACE service, but this difference was small and of borderline statistical significance. Likewise, no significant differences were seen in any of several quality measures or in patient satisfaction.

Our findings add to the available evidence supporting the use of physician assistants on academic general medicine services, and are germane to academic centers facing reductions in house staff availability and seeking alternative models of care for inpatients. Several specific characteristics of the PACE service and the implications of these should be considered:

  • The service accepted all patients, regardless of diagnosis, acuity, or complexity of illness. This was unlike many previously described nonhouse staff services which were more limited in scope, and allowed more flexibility with patient flow. However, in the end, patients on the PACE service did have a modestly lower case mix index and Charlson score, suggesting that, despite a lack of triage guidelines, there was some bias in the triage of admissions, possibly due to a perception that physician assistants should take care of lower complexity patients. If it is desirable to have a similar distribution of higher complexity patients across house staff and nonhouse staff services, extra efforts may be necessary to overcome this perception.

  • The service was geographically regionalized. Geographic regionalization offered many important advantages, especially with regards to communication among staff, nursing, and consultants, and allowed for multidisciplinary rounds. However, it is possible that the modest, but not statistically significant, trend toward an increased LOS seen on the PACE service might be a reflection of geographic admitting (less incentive to discharge since discharging a patient means taking a new admission).

  • The education and professional development of the physician assistants was a priority. Physician assistants had considerable autonomy and responsibility, and rather than being assigned only lower level administrative tasks, performed all aspects of patient care. They also received regular teaching from the hospitalists, attended house staff teaching conferences, and developed nonclinical roles in education and quality improvement. The higher standards expected of the physician assistants were quite possibly a factor in the quality of care delivered, and almost certainly contributed to physician assistant satisfaction and retention.

 

Our findings contrast with those of Myers et al.,9 who found that a nonteaching service staffed by hospitalists and nurse practitioners had a significantly lower median LOS and hospital charges compared to similar patients on resident‐based services. However, unlike ours, their service cared for a select patient population, and only accepted patients with chest pain at low risk for acute coronary syndrome. Van Rhee et al.10 found that physician assistants on a general medicine service used fewer resources for patients with pneumonia, stroke, and congestive heart failure than resident physicians, and did not exceed the resources used by residents in other diagnoses. The authors did not find a difference in LOS, but did find a significantly higher mortality among patients with pneumonia cared for by physician assistants.

Several limitations should be noted. First, the study was a retrospective analysis of administrative data rather than a randomized trial, and although we employed a standard approach to adjust for a wide range of patient characteristics including severity of illness, there may have been undetected differences in the patient populations studied that may have confounded our results. Second, resident moonlighters admitted patients to the PACE service and, at other times, to the house staff services, and this may have diluted any differences between the groups. However, when we limited our analysis to the subgroup of patients admitted during the day, similar results were obtained, with the exception that the PACE service had a lower rate of 14‐day readmissions, an unexpected finding deserving of further study. Third, the study was conducted in a single academic institution and our findings may not be generalizable to others with different needs and resources; indeed, the costs associated with implementing such a service may be prohibitive for some institutions. Fourth, because of simultaneous changes that were taking place in our residency program, we are unable to accurately assess the impact of the PACE service on resident duty hours. However, resident duty hours did not increase over this time period on the general medicine service, and implementation of the service allowed for redistribution of house staff to other services and positions. Fifth, patient satisfaction data were obtained from responses to the mailed Press‐Ganey survey, to which there is a relatively low response rate. Also, we did not survey providers regarding their satisfaction with the service during the study period. Sixth, the study had limited power to detect clinically important differences in mortality and ICU transfers. Finally, this study is unable to compare this particular model of incorporating midlevel providers into general medical services with other models, only with traditional house staff services.

Future research should focus on determining the most effective and efficient ways to incorporate midlevel providers on academic general medicine services. One important question from the standpoint of house staff training is whether such services should be separate but equal, or should house staff gain experience during residency working with midlevel providers, since they are likely to encounter them in the future whether they stay in academics or not. Different models of care will likely have large implications for the quality and efficiency of patient care, house staff education and satisfaction, and physician assistant job satisfaction and turnover.

In summary, our study demonstrates that a geographically regionalized, multidisciplinary service staffed by hospitalists and physician assistants can be a safe alternative to house staff‐based services for the care of general medicine inpatients in an academic medical center.

Midlevel providers (physician assistants and nurse practitioners) have long been employed by academic medical centers, predominantly on surgical services, or on medical subspecialty services, where they have typically had a limited scope of practice, focused in a narrowly defined area or set of procedures.17 In contrast, there are relatively few reports of experiences deploying midlevel providers to replace house staff on inpatient general medicine services in academic centers,810 and few studies of the effect of midlevel providers on quality and efficiency of care in the academic setting. Despite this, reductions in house officer duty hours as mandated by the Accreditation Council on Graduate Medical Education (ACGME)11 have resulted in academic centers increasingly using midlevel providers to decrease house staff workload on inpatient services.12, 13 In general, midlevel practitioners on general medicine services have been deployed to: (1) care for a population of patients separate from and in parallel with house staff; this population may be narrowly defined (eg, patients with chest pain) or not; (2) assist with the management of patients cared for by house staff by performing certain tasks (eg, scheduling appointments, discharging patients). Even as midlevel providers become more prevalent on academic general medicine services, the best model of care incorporating them into clinical care remains unclear, and few studies have rigorously examined the care provided on services that use them.

We developed an inpatient general medicine service within a large academic medical center staffed by physician assistants and hospitalists to help our residency program meet ACGME duty hour requirements. We hypothesized that by creating a service that is geographically localized and supervised by full‐time hospitalists, by instituting multidisciplinary rounds, and by investing in the professional development of highly‐skilled physician assistants, we could provide care for medically complex, acutely ill general medicine inpatients with similar quality and efficiency as compared to house staff teams. We report our experience during the first year of implementing the service, and compare quality and efficiency of care on this service with that of our traditional house staff services. We also evaluate the effects of this service on patient satisfaction and self‐reported house staff workload.

PATIENTS AND METHODS

Study Setting

The study was conducted in a 747‐bed urban, academic medical center in the northeastern United States. The hospital's human research committee reviewed and approved the study design. The hospital has accredited residency and fellowship programs in all major specialties. Prior to July 2005, physician assistants were employed only on surgical and medical subspecialty services (ie, bone marrow transplant, interventional cardiology); none were employed on the inpatient general medicine service. There were approximately 44,000 inpatient admissions during the year of the study, with approximately 6500 of these to the general medicine service.

Description of the General Medicine Service

The General Medicine Service consisted of 8 traditional house staff teams, with 1 attending, 1 junior or senior resident, 2 interns, and 1 or 2 medical students. These teams admitted patients on a rotating basis every fourth day. On 4 of these teams, the attending was a hospitalist, with clinical responsibility for the majority of the patients admitted to the team. On the remaining 4 teams, the teaching attending was a primary care physician or medical subspecialist, responsible for the direct care of a small number of the team's patients, with the remainder cared for by private primary care physicians or subspecialists.

Description of the Physician Assistant/Hospitalist Service

The Physician Assistant/Clinician Educator (PACE) service opened in July 2005, and consisted of 15 beds localized to 2 adjacent inpatient pods, staffed by a single cadre of nurses and medically staffed by 1 hospitalist and 2 physician assistants from 7:00 AM to 7:00 PM on weekdays and by 1 hospitalist, 1 physician assistant, and 1 moonlighter (usually a senior medical resident or fellow) from 7:00 AM to 7:00 PM on weekends. A moonlighter, typically a senior resident or medical subspecialty fellow, admitted patients and covered nights on the service from 7:00 PM to 7:00 AM 7 days a week. The daily census goal for the service was 15 patients, limited by the number of available beds on the 2 pods, and the service accepted admissions 24 hours per day, 7 days per week, whenever beds were available. Daily morning rounds occurred at 8:00 AM and included the hospitalist, physician assistants, nurses, a care coordinator, and a pharmacist. The PACE service did not have triage guidelines related to diagnosis, complexity, or acuity, but only accepted patients via the emergency department or via a primary care physician's office, and did not accept patients transferred from outside hospitals or from the intensive care units.

Physician Assistants

All of the physician assistants on the PACE service had prior inpatient medicine experience, ranging from 6 months to 5 years. The physician assistants worked in 3‐day to 6‐day blocks of 12‐hour shifts. Their clinical responsibilities were similar to those of interns at the study hospital, and included taking histories and performing physical examinations, writing notes and orders, reviewing and assimilating data, creating and updating patient signouts, completing discharge summaries, consulting other services as needed, and communicating with nurses and family members.

Many physician assistants also had nonclinical responsibilities, taking on physician‐mentored roles in education, quality improvement, and administration. They were involved in several initiatives: (1) developing a physician assistant curriculum in hospital medicine, (2) presenting at hospital‐wide physician assistant grand rounds, (3) surveying and tracking patient and family satisfaction on the service, (4) reviewing all 72‐hour hospital readmissions, intensive care unit transfers, and deaths on the service, and (5) maintaining the service's compliance with state regulations regarding physician assistant scope of practice and prescribing.

Hospitalists

The 3 hospitalists on the PACE service worked in 7‐day blocks of 12‐hour shifts (7:00 AM to 7:00 PM). They directly supervised the physician assistants and had no competing responsibilities. The hospitalists were all recent graduates of the study hospital's internal medicine residency, with no prior clinical experience beyond residency. All were planning to work on the service for 1 to 2 years before beginning a subspecialty fellowship. In addition to supervising the clinical work of the physician assistants, the hospitalists were responsible for teaching the physician assistants on rounds and in weekly didactic sessions, guided by a curriculum in hospital medicine that focused on the most common general medicine diagnoses seen on the PACE service. The medical director of the PACE service periodically reviewed each physician assistant's clinical experience, skills and knowledge base, and held semiannual feedback sessions.

Study Patients

All general medicine patients admitted to the PACE service from July 1, 2005 to June 30, 2006 comprised the study population. The comparison group consisted of general medicine patients admitted to the 8 house staff general medicine teams; patients transferred from an intensive care unit (ICU) or another facility were excluded in order to match the admission criteria for the PACE service and improve comparability between the 2 study arms.

Data Collection and Study Outcomes

We obtained all patient data from the hospital's administrative databases. We identified patients assigned to the PACE service or to the comparison group based on the admitting service, team, and attending. We obtained patient demographics, insurance, admission source and discharge destination, admission and discharge times, dates, diagnoses, and diagnosis‐related groups (DRGs), as well as dates and times of transfers to other services, including to the intensive care unit. We also obtained the Medicare case‐mix index (CMI, based on DRG weight), and calculated a Charlson score based on billing diagnoses coded in the year prior to the index admission.14 Outcomes included length of stay (LOS) to the nearest hour, in‐hospital mortality, transfers to the intensive care unit, readmissions to the study hospital within 72 hours, 14 days, and 30 days, and total costs as derived from the hospital's cost accounting system (Transition Systems Inc., Boston, MA). Other outcomes included patient satisfaction as measured by responses to the Press‐Ganey survey routinely administered to a randomly selected 70% of recently discharged patients and effect on self‐reported resident work hours.

Statistical Analysis

Patient demographics, clinical characteristics, and study outcomes are presented using proportions, means with standard deviations, and medians with inter‐quartile ranges as appropriate. Unadjusted differences in outcomes between the two services were calculated using univariable regression techniques with service as the independent variable and each outcome as the dependent variable. We used logistic regression for dichotomous outcomes (readmissions, ICU transfers, and inpatient mortality), and linear regression for log‐transformed LOS and log‐transformed total costs of care. To adjust each outcome for potential confounders, we then built multivariable regression models. Each potential confounder was entered into the model one at a time as the independent variable. All variables found to be significant predictors of the outcome at the P < 0.10 level were then retained in the final model along with service as the predictor of interest. We used general estimating equations in all multivariable models to adjust for clustering of patients by attending physician. For logistic regression models, the effect size is presented as an odds ratio (OR); for log‐transformed linear regression models, the effect size is presented as the percent difference between groups. We also performed 2 subgroup analyses, limited to (1) the patients with the 10 most common discharge DRGs, and (2) patients admitted between the hours of 7:00 AM and 7:00 PM to remove the effects of moonlighters performing the initial admission. Except as noted above, 2‐sided P values < 0.05 were considered significant. SAS 9.1 (SAS Institute, Cary, NC) was used for all analyses.

RESULTS

Patient Demographics

Table 1 shows patient demographics and clinical characteristics of the PACE service and the comparison group. Patients in the comparison group were slightly older and tended to have slightly higher CMI and Charlson scores. Patients on the PACE service were more likely to be admitted at night (10:00 PM to 7:00 AM; 43.8% versus 30.3%; P < 0.0001). There were no significant differences in sex, race, insurance, or percentage of patients discharged to home. The 10 most common DRGs in the comparison group accounted for 37.0% of discharges, and these same DRGs accounted for 37.5% of discharges on the PACE service (Table 2).

Patient Demographic and Clinical Characteristics
CharacteristicPACE Service (n = 992)House Staff Services (n = 4,202)P value
  • Numbers are percent of patients except where noted.

Age (years)   
184419.118.2 
456435.531.90.04
65+45.549.9 
Sex (% female)57.760.0NS
Race/ethnicity   
White57.359.3 
Black24.023.5NS
Hispanic14.113.3 
Other4.63.9 
Insurance   
Medicare41.943.8 
Commercial34.935.9 
Medicaid14.411.7NS
Free care4.53.9 
Self pay1.10.8 
Median income by zip code of residence, USD (IQR)45,517 (32,49362,932)45,517 (35,88963,275)NS
Case‐mix index, median (IQR)1.1 (0.81.5)1.2 (0.91.8)0.001
Charlson score   
027.224.9 
122.621.10.02
216.216.5 
3+34.037.6 
Admissions between 10:00 PM and 7:00 AM43.830.3<0.0001
Discharged to home81.180.5NS
Distribution of Top 10 Discharge Diagnosis Related Groups
Diagnosis‐Related Group at DischargePACE Service (n = 992)*House Staff Services (n = 4,202)*
  • Percent of all discharges by service.

Chest pain5.46.4
Esophagitis, gastroenteritis, and miscellaneous digestive disorders4.54.4
Heart failure and shock3.44.6
Simple pneumonia and pleurisy2.74.4
Kidney and urinary tract infections4.73.2
Chronic obstructive pulmonary disease4.03.3
Renal failure2.73.5
Gastrointestinal hemorrhage3.72.7
Nutritional and miscellaneous metabolic disorders3.32.4
Disorders of the pancreas except malignancy3.12.1
Cumulative percent37.537.0

Efficiency and Quality of Care

Table 3 compares the performance of the PACE service and the comparison group on several efficiency and quality measures. Unadjusted LOS was not significantly different, and adjusted LOS was slightly but not statistically significantly higher on the study service (adjusted LOS 5.0% higher; 95% confidence interval [CI], 0.4% to +10%). Unadjusted and adjusted total costs of care were marginally lower on the study service (adjusted total cost of care 3.9% lower; 95% CI, 7.5% to 0.3%).

Efficiency and Quality Measures for the PACE Service and House Staff Services
 PACE ServiceHouse Staff ServicesUnadjusted % Difference (95%CI)Adjusted % Difference (95%CI)*
 PACE ServiceHouse Staff ServicesUnadjusted OR (95% CI)Adjusted OR (95% CI)
  • All adjusted models adjusted for clustering by attending physician.

  • Adjusted for age, race, Charlson score, time of admission, insurer, and Case Mix Index (CMI).

  • P ≪ 0.001.

  • P < 0.05.

  • Adjusted for age, sex, race, Charlson score, time of admission, insurer, and CMI, and log of median income by zip code.

  • |Adjusted for race, Charlson score, insurer, CMI, and discharge to home or skilled nursing facility.

  • Adjusted for age, sex, race, Charlson score, CMI, time of admission, and discharge to home or skilled nursing facility.

  • Adjusted for sex, race, Charlson score, CMI, and log of median income by zip code.

Efficiency measure    
Length of stay, days, median (IQR)2.6 (1.6, 4.4)2.6 (1.4, 4.6)+0.1% (5.6% to +6.1%)+5.0% (0.4% to +10.0%)
Total costs, USD, median (IQR)4,536 (2,848, 7,201)4,749 (3,046, 8,161)9.1% (14.0% to 3.8%)3.9% (7.5% to 0.3%)
Quality measure    
72‐hour readmissions/100 discharges0.81.30.6 (0.31.3)0.7 (0.21.8)
14‐day readmissions/100 discharges5.45.41.0 (0.71.4)1.1 (0.81.4)
30‐day readmissions/100 discharges8.08.11.0 (0.81.3)1.1 (0.91.3)
ICU transfers/100 discharges2.02.30.9 (0.51.4)1.4 (0.82.4)#
Inpatient mortality/100 discharges0.71.20.6 (0.31.3)0.8 (0.31.8)**

We found no differences between the PACE service and comparison group in unadjusted rates of hospital readmissions within 72 hours, 14 days, and 30 days, transfer to the intensive care units, or inpatient mortality (Table 3). The associated ORs for each outcome were similar after adjusting for patient demographics and clinical characteristics including severity of illness, as well as for clustering by attending physician.

Subgroup Analyses

When the analysis was limited to the subset of patients with the 10 most common discharge DRGs, the difference in adjusted total cost of care was similar but lost statistical significance (4.0% lower on PACE service; 95% CI, 11.0% to +3.3%). In this subgroup, LOS, readmission rates, and ICU transfer rates were not different. ORs for mortality could not be calculated because there were no deaths in this subgroup on the PACE service (data not shown). When analysis was limited to daytime admissions (to remove any potential effect of admitting by a moonlighter), the difference in total cost of care was attenuated and lost statistical significance (0.2% lower on PACE service; 95%CI, 5.9% to +5.5%). No differences were seen in LOS, mortality, and ICU transfers (data not shown). However, 14‐day readmissions (but not 72‐hour or 30‐day readmissions) were lower on the PACE service (OR, 0.49; 95% CI, 0.25‐0.93).

Patient Satisfaction

Patients were similarly satisfied with their care on the PACE service and on the house staff services. In specific areas and globally, percentages of patients satisfied with their physicians and with the discharge process were not different, as measured by the Press‐Ganey survey (Press‐Ganey Associates, South Bend, IN; Figures 1 and 2). The survey distinguishes between attendings and residents, but not physician assistants; therefore, Figure 1 only includes responses to the attending questions. Given the sampling procedure of the Press‐Ganey survey, exact response rates cannot be calculated, but Press‐Ganey reports a response rate of about 40% for the English survey and about 20% for the Spanish survey.

Figure 1
Press‐Ganey physician scores (% satisfied or very satisfied). P = NS for all comparisons.
Figure 2
Press‐Ganey discharge scores (% satisfied or very satisfied), P = NS for all comparisons.

Resident Duty Hours

Comparing the same month 1 year prior to implementation of the PACE service, mean self‐reported resident duty hours on the general medicine service were unchanged; however, self‐reported data were incomplete, and multiple changes took place in the residency program during the study period. For example, implementation of the PACE service allowed for the dissolution of one full house staff general medicine team and redistribution of these house staff to night float positions and an expanded medical intensive care unit.

Costs of Implementation

The costs associated with implementing the PACE service included physician and physician assistant salaries (2.5 full‐time physicians, 5 full‐time physician assistants, plus fringe) and night coverage by resident and fellow moonlighters (without fringe, and estimated at 50% effort given other moonlighter coverage responsibilities on subspecialty services). We estimated these costs at $257.50/patient‐day ($115/patient‐day for attending physician compensation, $110/patient‐day for physician assistant compensation, and $32.50/patient‐day for moonlighting coverage).

DISCUSSION

As academic centers struggle with developing a workforce to provide patient care no longer provided by residents, questions about the ideal structure of nonhouse staff inpatient services abound. Although solutions to this problem will be determined to some extent by local factors such as institutional culture and resources, some lessons learned in developing such services will be more widely applicable. We found that by implementing a geographically localized, physician assistant‐staffed hospitalist service, we were able to provide care of similar quality and efficiency to that of traditional house staff services, despite inexperienced hospitalists staffing the service and a medical residency program commonly recognized as one of the best in the country. Adjusted total costs were slightly lower on the PACE service, but this difference was small and of borderline statistical significance. Likewise, no significant differences were seen in any of several quality measures or in patient satisfaction.

Our findings add to the available evidence supporting the use of physician assistants on academic general medicine services, and are germane to academic centers facing reductions in house staff availability and seeking alternative models of care for inpatients. Several specific characteristics of the PACE service and the implications of these should be considered:

  • The service accepted all patients, regardless of diagnosis, acuity, or complexity of illness. This was unlike many previously described nonhouse staff services which were more limited in scope, and allowed more flexibility with patient flow. However, in the end, patients on the PACE service did have a modestly lower case mix index and Charlson score, suggesting that, despite a lack of triage guidelines, there was some bias in the triage of admissions, possibly due to a perception that physician assistants should take care of lower complexity patients. If it is desirable to have a similar distribution of higher complexity patients across house staff and nonhouse staff services, extra efforts may be necessary to overcome this perception.

  • The service was geographically regionalized. Geographic regionalization offered many important advantages, especially with regards to communication among staff, nursing, and consultants, and allowed for multidisciplinary rounds. However, it is possible that the modest, but not statistically significant, trend toward an increased LOS seen on the PACE service might be a reflection of geographic admitting (less incentive to discharge since discharging a patient means taking a new admission).

  • The education and professional development of the physician assistants was a priority. Physician assistants had considerable autonomy and responsibility, and rather than being assigned only lower level administrative tasks, performed all aspects of patient care. They also received regular teaching from the hospitalists, attended house staff teaching conferences, and developed nonclinical roles in education and quality improvement. The higher standards expected of the physician assistants were quite possibly a factor in the quality of care delivered, and almost certainly contributed to physician assistant satisfaction and retention.

 

Our findings contrast with those of Myers et al.,9 who found that a nonteaching service staffed by hospitalists and nurse practitioners had a significantly lower median LOS and hospital charges compared to similar patients on resident‐based services. However, unlike ours, their service cared for a select patient population, and only accepted patients with chest pain at low risk for acute coronary syndrome. Van Rhee et al.10 found that physician assistants on a general medicine service used fewer resources for patients with pneumonia, stroke, and congestive heart failure than resident physicians, and did not exceed the resources used by residents in other diagnoses. The authors did not find a difference in LOS, but did find a significantly higher mortality among patients with pneumonia cared for by physician assistants.

Several limitations should be noted. First, the study was a retrospective analysis of administrative data rather than a randomized trial, and although we employed a standard approach to adjust for a wide range of patient characteristics including severity of illness, there may have been undetected differences in the patient populations studied that may have confounded our results. Second, resident moonlighters admitted patients to the PACE service and, at other times, to the house staff services, and this may have diluted any differences between the groups. However, when we limited our analysis to the subgroup of patients admitted during the day, similar results were obtained, with the exception that the PACE service had a lower rate of 14‐day readmissions, an unexpected finding deserving of further study. Third, the study was conducted in a single academic institution and our findings may not be generalizable to others with different needs and resources; indeed, the costs associated with implementing such a service may be prohibitive for some institutions. Fourth, because of simultaneous changes that were taking place in our residency program, we are unable to accurately assess the impact of the PACE service on resident duty hours. However, resident duty hours did not increase over this time period on the general medicine service, and implementation of the service allowed for redistribution of house staff to other services and positions. Fifth, patient satisfaction data were obtained from responses to the mailed Press‐Ganey survey, to which there is a relatively low response rate. Also, we did not survey providers regarding their satisfaction with the service during the study period. Sixth, the study had limited power to detect clinically important differences in mortality and ICU transfers. Finally, this study is unable to compare this particular model of incorporating midlevel providers into general medical services with other models, only with traditional house staff services.

Future research should focus on determining the most effective and efficient ways to incorporate midlevel providers on academic general medicine services. One important question from the standpoint of house staff training is whether such services should be separate but equal, or should house staff gain experience during residency working with midlevel providers, since they are likely to encounter them in the future whether they stay in academics or not. Different models of care will likely have large implications for the quality and efficiency of patient care, house staff education and satisfaction, and physician assistant job satisfaction and turnover.

In summary, our study demonstrates that a geographically regionalized, multidisciplinary service staffed by hospitalists and physician assistants can be a safe alternative to house staff‐based services for the care of general medicine inpatients in an academic medical center.

References
  1. Heinrich JJ,Fichandler BC,Beinfield M,Frazier W,Krizek TJ,Baue AE.The physician's assistant as resident on surgical service. An example of creative problem solving in surgical manpower.Arch Surg.1980;115:310314.
  2. DeMots H,Coombs B,Murphy E,Palac R.Coronary arteriography performed by a physician assistant.Am J Cardiol.1987;60:784787.
  3. O'Rourke RA.The specialized physician assistant: an alternative to the clinical cardiology trainee.Am J Cardiol.1987;60:901902.
  4. Russell JC,Kaplowe J,Heinrich J.One hospital's successful 20‐year experience with physician assistants in graduate medical education.Acad Med.1999;74:641645.
  5. Thourani VH,Miller JI.Physicians assistants in cardiothoracic surgery: a 30‐year experience in a university center.Ann Thorac Surg.2006;81:195199; discussion 199–200.
  6. Oswanski MF,Sharma OP,Raj SS.Comparative review of use of physician assistants in a level I trauma center.Am Surg.2004;70:272279.
  7. Reines HD,Robinson L,Duggan M,O'Brien BM,Aulenbach K.Integrating midlevel practitioners into a teaching service.Am J Surg.2006;192:119124.
  8. Howie JN,Erickson M.Acute care nurse practitioners: creating and implementing a model of care for an inpatient general medical service.Am J Crit Care.2002;11:448458.
  9. Myers JS,Bellini LM,Rohrbach J,Shofer FS,Hollander JE.Improving resource utilization in a teaching hospital: development of a nonteaching service for chest pain admissions.Acad Med.2006;81:432435.
  10. Van Rhee J,Ritchie J,Eward AM.Resource use by physician assistant services versus teaching services.JAAPA.2002;15:3338.
  11. Philibert I,Friedmann P,Williams WT, for the ACGME Work Group on Resident Duty Hours, Accreditation Council for Graduate Medical Education.New requirements for resident duty hours.JAMA.2002;288:11121114.
  12. Riportella‐Muller R,Libby D,Kindig D.The substitution of physician assistants and nurse practitioners for physician residents in teaching hospitals.Health Aff.1995;14:181191.
  13. Todd BA,Resnick A,Stuhlemmer R,Morris JB,Mullen J.Challenges of the 80‐hour resident work rules: collaboration between surgeons and nonphysician practitioners.Surg Clin North Am.2004;84:15731586.
  14. Deyo RA,Cherkin DC,Ciol MA.Adapting a clinical comorbidity index for use with ICD‐9‐CM administrative databases.J Clin Epidemiol.1992;45:613619.
References
  1. Heinrich JJ,Fichandler BC,Beinfield M,Frazier W,Krizek TJ,Baue AE.The physician's assistant as resident on surgical service. An example of creative problem solving in surgical manpower.Arch Surg.1980;115:310314.
  2. DeMots H,Coombs B,Murphy E,Palac R.Coronary arteriography performed by a physician assistant.Am J Cardiol.1987;60:784787.
  3. O'Rourke RA.The specialized physician assistant: an alternative to the clinical cardiology trainee.Am J Cardiol.1987;60:901902.
  4. Russell JC,Kaplowe J,Heinrich J.One hospital's successful 20‐year experience with physician assistants in graduate medical education.Acad Med.1999;74:641645.
  5. Thourani VH,Miller JI.Physicians assistants in cardiothoracic surgery: a 30‐year experience in a university center.Ann Thorac Surg.2006;81:195199; discussion 199–200.
  6. Oswanski MF,Sharma OP,Raj SS.Comparative review of use of physician assistants in a level I trauma center.Am Surg.2004;70:272279.
  7. Reines HD,Robinson L,Duggan M,O'Brien BM,Aulenbach K.Integrating midlevel practitioners into a teaching service.Am J Surg.2006;192:119124.
  8. Howie JN,Erickson M.Acute care nurse practitioners: creating and implementing a model of care for an inpatient general medical service.Am J Crit Care.2002;11:448458.
  9. Myers JS,Bellini LM,Rohrbach J,Shofer FS,Hollander JE.Improving resource utilization in a teaching hospital: development of a nonteaching service for chest pain admissions.Acad Med.2006;81:432435.
  10. Van Rhee J,Ritchie J,Eward AM.Resource use by physician assistant services versus teaching services.JAAPA.2002;15:3338.
  11. Philibert I,Friedmann P,Williams WT, for the ACGME Work Group on Resident Duty Hours, Accreditation Council for Graduate Medical Education.New requirements for resident duty hours.JAMA.2002;288:11121114.
  12. Riportella‐Muller R,Libby D,Kindig D.The substitution of physician assistants and nurse practitioners for physician residents in teaching hospitals.Health Aff.1995;14:181191.
  13. Todd BA,Resnick A,Stuhlemmer R,Morris JB,Mullen J.Challenges of the 80‐hour resident work rules: collaboration between surgeons and nonphysician practitioners.Surg Clin North Am.2004;84:15731586.
  14. Deyo RA,Cherkin DC,Ciol MA.Adapting a clinical comorbidity index for use with ICD‐9‐CM administrative databases.J Clin Epidemiol.1992;45:613619.
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Journal of Hospital Medicine - 3(5)
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Journal of Hospital Medicine - 3(5)
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361-368
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Implementation of a physician assistant/hospitalist service in an academic medical center: Impact on efficiency and patient outcomes
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Implementation of a physician assistant/hospitalist service in an academic medical center: Impact on efficiency and patient outcomes
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academic medical centers, inpatients, internship and residency, physician assistants, program evaluation, quality of health care
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academic medical centers, inpatients, internship and residency, physician assistants, program evaluation, quality of health care
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