Julie Grunawalt, MS, RN, GCNC‐BC

Hyperglycemia is common in hospitalized patients, and hyperglycemia has been associated with poor hospital outcomes. The adverse physiologic effects of acute hyperglycemia are well established1 and several clinical studies have linked hyperglycemia with poor clinical outcomes in certain patient populations.28 Although the optimal target range for inpatient glycemic control has not yet been defined, these studies support the goal of metabolic control for hospital patients. However, there are many barriers to achieving adequate glycemic control in the hospital, and blood glucoses in the hospital are often far from recommended targets.9, 10 One barrier appears to be the low priority given to glycemic control in the hospital. Hyperglycemia in the hospital is often ignored,11 and insulin regimens are often chosen for simplicity as opposed to effectiveness.12 Other barriers to glycemic control in the hospital include the physiologic effects (stress) of acute illness, and the frequent nutritional changes and interruptions that occur.

Most hyperglycemic patients on a general medicine unit are treated with subcutaneous insulin, but the optimal strategy for prescribing insulin in the hospital remains uncertain. A technical review of the literature on the management of diabetes in the hospital setting from 2004 recommends prescribing insulin in a way that mimics physiologic insulin secretion (ie, physiologic or basal‐bolus insulin).1 This approach has been promulgated by experts, but there has been very little research to support these recommendations. One small, randomized trial concluded that a basal‐bolus approach achieved better glycemic control than the use of sliding‐scale insulin alone,13 and 2 quality improvement studies using a before/after design have demonstrated improvements in glycemic control after the implementation of interventions designed to encourage physiologic insulin use.14, 15

In this study we hypothesized that a few simple interventions (education for physicians and nurses, and a standardized insulin order form) would lead to a higher rate of basal‐bolus insulin use and simultaneously improve glycemic control and patient safety.

Methods

Results

A total of 245 patients provided 1315 patient‐days. Patient demographics are shown in Table 2. The patients' weight, length‐of‐stay, and primary diagnoses were similar across the 3 groups. There was a higher percentage of males in the IG as compared to the HCG.

Table 3 shows the insulin regimens used in the different groups. The use of basal insulin was similar between groups. Congruent with the goals of the education session and the order set, patients in the IG were more likely to be treated with a combination of basal and nutritional insulin than patients in the other groups. Patients in the HCG were more likely to be treated with a premixed insulin than patients in the other groups. However, even when premixed insulin was categorized as a form of basal plus nutritional insulin and combined into a composite group with the combined basal and nutritional days, this type of regimen remained more common in the IG than in the HCG. The rate of sliding scale insulin use alone (ie, without any scheduled insulin) was similar in the 3 groups.

Other relevant measures are also shown in Table 3. The use of oral diabetes agents was similar in the 3 groups. The use of a nonoral feeding route (eg, tube feeding or parenteral nutrition) was infrequent.

A comparison of glycemic control in the three groups is shown in Table 4. In contrast to the CCG, patients in the IG experienced more days within the target glucose range (17% vs. 10.6%, P < 0.01), fewer days with severe hyperglycemia (48.3% vs. 59.2%, P < 0.01), and had a lower day‐weighted average blood glucose (195.9 vs. 212.6, P < 0.01). Compared to the HCG, patients in the IG experienced similar rates of hyperglycemia, but fewer hypoglycemic days (5.1% vs. 9.2%, P = 0.02).

The percentages of patients with severe hyperglycemia in each group are shown in Figure 1 by hospital day. Severe hyperglycemia was common, but there was a trend towards a decrease in the prevalence of severe hyperglycemia with increasing hospital days for all study groups, although it was consistently higher in the CCG than in the IG. Figure 2 shows the types of insulin regimens used by hospital day (composite for all groups). The use of basal plus nutritional insulin (the recommended regimen) increased gradually with increasing hospital days. When taken together, the information in both figures support the hypothesis that the use of the recommended insulin regimen may have contributed to the modest improvements in glycemic control seen in the IG.

Figure 1

Figure 2

In the final adjusted regression model, the intervention had a positive impact on glycemic control (Table 5). Subjects in the IG had a 72% increase in the odds of being in the target glucose range when compared to subjects in the CCG (P = 0.01). In addition, subjects in the IG had a 35% reduction in the odds of being severely hyperglycemic when compared to those in the CCG (P < 0.01). Finally, the odds ratio (OR) for being hypoglycemic among intervention subjects was 0.59 (P = 0.06) when compared to subjects in the CCG and 0.48 (P = 0.01) when compared to subjects in the HCG.

Discussion

In this study, we investigated the effects of a standardized insulin order set, coupled with physician and nurse education, on glycemic control in hyperglycemic hospitalized patients. These interventions were designed to encourage a standardized approach to the treatment of hyperglycemia in hospitalized patients, based on the principles of physiologic insulin use, as described above. Our data suggest that the interventions did, indeed, alter the way insulin was prescribed, as more patients in the IG received a combination of basal plus nutritional insulin (the recommended regimen) than in the other groups. These interventions were associated with improved glycemic outcomes in the IG as compared to the CCG. The IG experienced a higher percentage of days in the target range and a trend toward fewer hypoglycemic days than the CCG. Although the IG experienced a similar percentage of days in the target range, it had significantly fewer hypoglycemic days than the HCG.

It is useful to consider the results of our study in the context of 2 other similar studies performed by Schnipper et al.14 and Maynard et al.15 Although each of these 3 studies have different study designs, they are similar in intent (to test the effects of simple quality improvement interventions on glycemic control in the hospital) and results (all showed significant improvements in some aspect of glycemic control). In our study, and the study by Maynard et al.,15 the interventions also led to decreases in the rates of hypoglycemia, whereas Schnipper et al.14 observed no difference in hypoglycemia. Of interest, in each of the three studies the interventions were associated with an increase in the use of some type of scheduled insulin. In our study and the study from Schnipper et al.14 the baseline use of basal insulin was quite high, and the interventions were associated with a significant increase in the addition of nutritional insulin. In the Maynard et al.15 study, the baseline use of sliding scale insulin alone was prevalent, and the interventions resulted in an increase in the use of basal insulin. The results of these studies, taken together, prompt us to conclude that the interventions employed in these studies are likely to lead to more frequent prescription of scheduled (anticipatory) insulin, and a modest improvement in glycemic control, without an increase (and perhaps with a decrease) in hypoglycemia.

A few of our study results are unexpected, or difficult to explain. In contrast to the other studies discussed above, our interventions did not affect the frequency of the use of sliding‐scale insulin alone (without any scheduled insulin), which was similar in the 3 groups. Although the reason for this is uncertain, we hypothesize that the high baseline use of basal insulin in our institution, and the lack of a hard stop preventing the use of sliding scale insulin alone explain this finding. Also, it is difficult to explain why measures of hyperglycemia were similar between the IG and the HCG despite the fact that the HCG was less often treated with a combination of basal and nutritional insulin and more often treated with mixed insulin.

There are several different mechanisms by which the interventions might have resulted in improved glycemic control in the IG compared to CCG. Our data clearly shows that insulin was prescribed differently in the IG, and the more frequent use of a combination of scheduled basal and nutritional insulin might have contributed to the differences between the groups. However, the effects of our interventions clearly went beyond physician education into the realm of true process improvement and standardization. The standardized order form was designed to prompt physicians to use a basal‐bolus insulin regimen. The order form also created nursing expectations of how insulin should be ordered, and clarified the roles of the different insulins that were prescribed.

On the medication administration record, each insulin was labeled as basal insulin (to be given even when fasting) or nutritional insulin (to be given along with the meal). The nurses caring for the IG also attended an education program that reinforced the role of the nurse in the bedside management of insulin administration. Specifically, nurses were taught to assess the premeal blood glucose and the patient's nutritional situation before giving the nutritional insulin (ie, Does the patient have food available? Will he tolerate eating the food?). In situations where is was not clear if the patient would be able to tolerate the ordered nutrition, the order set empowered the nurse to give the nutritional insulin after the meal, and to reduce the dose to match the patient's actual intake. These interventions resulted in some fundamental improvements in the nursing process of delivering insulin to the patient, and these changes might have resulted in improvements via mechanisms that are difficult to directly measure. Since the same physicians cared for both the IG and the CCG, interventions other than physician education clearly contributed to the observed improvements in the IG.

This study was not a randomized study, and there could be important undetected differences between the groups. However, all of the patients were admitted to the General Medicine Inpatient Services and the comparison of the general patient demographics and primary diagnoses between the groups do not suggest major differences.

Although the improvements in glycemic control seen in this study were statistically significant, they were quantitatively modest. The rates of hyperglycemia seen in this study, on the other hand, are quite remarkable. Both the American Diabetes Association and the American College of Endocrinology have recommended that blood glucoses in hospitalized patients not exceed a maximum value of 180 mg/dL, but the day‐weighted average blood glucose in this study was above that for each group. Even in the IG, over 80% of all patient‐days included at least 1 blood glucose value outside of the target range. These data suggest that better strategies for achieving metabolic control in hospitalized patients are needed.

It is worth mentioning that our interventions were not aggressively enforced. While the use of the order set was mandatory for the IG, it was flexible enough to allow for substantial practice variation, especially with respect to the dose of insulin prescribed. Although the education sessions discussed the specifics of insulin dosing in hospitalized patients, the order form did not offer dosing guidelines. It is possible that our interventions may have had a larger impact if a starting dose of insulin had been specified on the form. Although the insulin order form prompted physicians to act, there were no forced functions. Also, not all house staff attended the education sessions for physicians, and there was no feedback provided to physicians related to how they might improve their adherence to the recommendations presented in the educational module. Therefore, it is likely that more aggressive interventions could have led to greater changes in physician practice.

In conclusion, this study demonstrates that interventions including physician and nurse education and a standardized insulin order set can lead to improvement in glycemic control and patient safety in hospitalized patients treated with subcutaneous insulin. However, the observed improvements are modest, and poor metabolic control remains common, despite these interventions. These data suggest that standardization of the process of ordering and delivering subcutaneous insulin in the hospital may lead to a reduction in both hyperglycemia and hypoglycemia. However, it is clear that the interventions used in this study were not potent enough to achieve the recommended glycemic targets for the majority of patients. Additional research is needed to determine the best strategy for achieving safe and effective metabolic control in hospitalized, hyperglycemic, noncritically ill patients.

Hyperglycemia is common in hospitalized patients, and hyperglycemia has been associated with poor hospital outcomes. The adverse physiologic effects of acute hyperglycemia are well established1 and several clinical studies have linked hyperglycemia with poor clinical outcomes in certain patient populations.28 Although the optimal target range for inpatient glycemic control has not yet been defined, these studies support the goal of metabolic control for hospital patients. However, there are many barriers to achieving adequate glycemic control in the hospital, and blood glucoses in the hospital are often far from recommended targets.9, 10 One barrier appears to be the low priority given to glycemic control in the hospital. Hyperglycemia in the hospital is often ignored,11 and insulin regimens are often chosen for simplicity as opposed to effectiveness.12 Other barriers to glycemic control in the hospital include the physiologic effects (stress) of acute illness, and the frequent nutritional changes and interruptions that occur.

Most hyperglycemic patients on a general medicine unit are treated with subcutaneous insulin, but the optimal strategy for prescribing insulin in the hospital remains uncertain. A technical review of the literature on the management of diabetes in the hospital setting from 2004 recommends prescribing insulin in a way that mimics physiologic insulin secretion (ie, physiologic or basal‐bolus insulin).1 This approach has been promulgated by experts, but there has been very little research to support these recommendations. One small, randomized trial concluded that a basal‐bolus approach achieved better glycemic control than the use of sliding‐scale insulin alone,13 and 2 quality improvement studies using a before/after design have demonstrated improvements in glycemic control after the implementation of interventions designed to encourage physiologic insulin use.14, 15

In this study we hypothesized that a few simple interventions (education for physicians and nurses, and a standardized insulin order form) would lead to a higher rate of basal‐bolus insulin use and simultaneously improve glycemic control and patient safety.

Methods

Results

A total of 245 patients provided 1315 patient‐days. Patient demographics are shown in Table 2. The patients' weight, length‐of‐stay, and primary diagnoses were similar across the 3 groups. There was a higher percentage of males in the IG as compared to the HCG.

Table 3 shows the insulin regimens used in the different groups. The use of basal insulin was similar between groups. Congruent with the goals of the education session and the order set, patients in the IG were more likely to be treated with a combination of basal and nutritional insulin than patients in the other groups. Patients in the HCG were more likely to be treated with a premixed insulin than patients in the other groups. However, even when premixed insulin was categorized as a form of basal plus nutritional insulin and combined into a composite group with the combined basal and nutritional days, this type of regimen remained more common in the IG than in the HCG. The rate of sliding scale insulin use alone (ie, without any scheduled insulin) was similar in the 3 groups.

Other relevant measures are also shown in Table 3. The use of oral diabetes agents was similar in the 3 groups. The use of a nonoral feeding route (eg, tube feeding or parenteral nutrition) was infrequent.

A comparison of glycemic control in the three groups is shown in Table 4. In contrast to the CCG, patients in the IG experienced more days within the target glucose range (17% vs. 10.6%, P < 0.01), fewer days with severe hyperglycemia (48.3% vs. 59.2%, P < 0.01), and had a lower day‐weighted average blood glucose (195.9 vs. 212.6, P < 0.01). Compared to the HCG, patients in the IG experienced similar rates of hyperglycemia, but fewer hypoglycemic days (5.1% vs. 9.2%, P = 0.02).

The percentages of patients with severe hyperglycemia in each group are shown in Figure 1 by hospital day. Severe hyperglycemia was common, but there was a trend towards a decrease in the prevalence of severe hyperglycemia with increasing hospital days for all study groups, although it was consistently higher in the CCG than in the IG. Figure 2 shows the types of insulin regimens used by hospital day (composite for all groups). The use of basal plus nutritional insulin (the recommended regimen) increased gradually with increasing hospital days. When taken together, the information in both figures support the hypothesis that the use of the recommended insulin regimen may have contributed to the modest improvements in glycemic control seen in the IG.

Figure 1

Figure 2

In the final adjusted regression model, the intervention had a positive impact on glycemic control (Table 5). Subjects in the IG had a 72% increase in the odds of being in the target glucose range when compared to subjects in the CCG (P = 0.01). In addition, subjects in the IG had a 35% reduction in the odds of being severely hyperglycemic when compared to those in the CCG (P < 0.01). Finally, the odds ratio (OR) for being hypoglycemic among intervention subjects was 0.59 (P = 0.06) when compared to subjects in the CCG and 0.48 (P = 0.01) when compared to subjects in the HCG.

Discussion

In this study, we investigated the effects of a standardized insulin order set, coupled with physician and nurse education, on glycemic control in hyperglycemic hospitalized patients. These interventions were designed to encourage a standardized approach to the treatment of hyperglycemia in hospitalized patients, based on the principles of physiologic insulin use, as described above. Our data suggest that the interventions did, indeed, alter the way insulin was prescribed, as more patients in the IG received a combination of basal plus nutritional insulin (the recommended regimen) than in the other groups. These interventions were associated with improved glycemic outcomes in the IG as compared to the CCG. The IG experienced a higher percentage of days in the target range and a trend toward fewer hypoglycemic days than the CCG. Although the IG experienced a similar percentage of days in the target range, it had significantly fewer hypoglycemic days than the HCG.

It is useful to consider the results of our study in the context of 2 other similar studies performed by Schnipper et al.14 and Maynard et al.15 Although each of these 3 studies have different study designs, they are similar in intent (to test the effects of simple quality improvement interventions on glycemic control in the hospital) and results (all showed significant improvements in some aspect of glycemic control). In our study, and the study by Maynard et al.,15 the interventions also led to decreases in the rates of hypoglycemia, whereas Schnipper et al.14 observed no difference in hypoglycemia. Of interest, in each of the three studies the interventions were associated with an increase in the use of some type of scheduled insulin. In our study and the study from Schnipper et al.14 the baseline use of basal insulin was quite high, and the interventions were associated with a significant increase in the addition of nutritional insulin. In the Maynard et al.15 study, the baseline use of sliding scale insulin alone was prevalent, and the interventions resulted in an increase in the use of basal insulin. The results of these studies, taken together, prompt us to conclude that the interventions employed in these studies are likely to lead to more frequent prescription of scheduled (anticipatory) insulin, and a modest improvement in glycemic control, without an increase (and perhaps with a decrease) in hypoglycemia.

A few of our study results are unexpected, or difficult to explain. In contrast to the other studies discussed above, our interventions did not affect the frequency of the use of sliding‐scale insulin alone (without any scheduled insulin), which was similar in the 3 groups. Although the reason for this is uncertain, we hypothesize that the high baseline use of basal insulin in our institution, and the lack of a hard stop preventing the use of sliding scale insulin alone explain this finding. Also, it is difficult to explain why measures of hyperglycemia were similar between the IG and the HCG despite the fact that the HCG was less often treated with a combination of basal and nutritional insulin and more often treated with mixed insulin.

There are several different mechanisms by which the interventions might have resulted in improved glycemic control in the IG compared to CCG. Our data clearly shows that insulin was prescribed differently in the IG, and the more frequent use of a combination of scheduled basal and nutritional insulin might have contributed to the differences between the groups. However, the effects of our interventions clearly went beyond physician education into the realm of true process improvement and standardization. The standardized order form was designed to prompt physicians to use a basal‐bolus insulin regimen. The order form also created nursing expectations of how insulin should be ordered, and clarified the roles of the different insulins that were prescribed.

On the medication administration record, each insulin was labeled as basal insulin (to be given even when fasting) or nutritional insulin (to be given along with the meal). The nurses caring for the IG also attended an education program that reinforced the role of the nurse in the bedside management of insulin administration. Specifically, nurses were taught to assess the premeal blood glucose and the patient's nutritional situation before giving the nutritional insulin (ie, Does the patient have food available? Will he tolerate eating the food?). In situations where is was not clear if the patient would be able to tolerate the ordered nutrition, the order set empowered the nurse to give the nutritional insulin after the meal, and to reduce the dose to match the patient's actual intake. These interventions resulted in some fundamental improvements in the nursing process of delivering insulin to the patient, and these changes might have resulted in improvements via mechanisms that are difficult to directly measure. Since the same physicians cared for both the IG and the CCG, interventions other than physician education clearly contributed to the observed improvements in the IG.

This study was not a randomized study, and there could be important undetected differences between the groups. However, all of the patients were admitted to the General Medicine Inpatient Services and the comparison of the general patient demographics and primary diagnoses between the groups do not suggest major differences.

Although the improvements in glycemic control seen in this study were statistically significant, they were quantitatively modest. The rates of hyperglycemia seen in this study, on the other hand, are quite remarkable. Both the American Diabetes Association and the American College of Endocrinology have recommended that blood glucoses in hospitalized patients not exceed a maximum value of 180 mg/dL, but the day‐weighted average blood glucose in this study was above that for each group. Even in the IG, over 80% of all patient‐days included at least 1 blood glucose value outside of the target range. These data suggest that better strategies for achieving metabolic control in hospitalized patients are needed.

It is worth mentioning that our interventions were not aggressively enforced. While the use of the order set was mandatory for the IG, it was flexible enough to allow for substantial practice variation, especially with respect to the dose of insulin prescribed. Although the education sessions discussed the specifics of insulin dosing in hospitalized patients, the order form did not offer dosing guidelines. It is possible that our interventions may have had a larger impact if a starting dose of insulin had been specified on the form. Although the insulin order form prompted physicians to act, there were no forced functions. Also, not all house staff attended the education sessions for physicians, and there was no feedback provided to physicians related to how they might improve their adherence to the recommendations presented in the educational module. Therefore, it is likely that more aggressive interventions could have led to greater changes in physician practice.

In conclusion, this study demonstrates that interventions including physician and nurse education and a standardized insulin order set can lead to improvement in glycemic control and patient safety in hospitalized patients treated with subcutaneous insulin. However, the observed improvements are modest, and poor metabolic control remains common, despite these interventions. These data suggest that standardization of the process of ordering and delivering subcutaneous insulin in the hospital may lead to a reduction in both hyperglycemia and hypoglycemia. However, it is clear that the interventions used in this study were not potent enough to achieve the recommended glycemic targets for the majority of patients. Additional research is needed to determine the best strategy for achieving safe and effective metabolic control in hospitalized, hyperglycemic, noncritically ill patients.

Hyperglycemia is common in hospitalized patients, and hyperglycemia has been associated with poor hospital outcomes. The adverse physiologic effects of acute hyperglycemia are well established1 and several clinical studies have linked hyperglycemia with poor clinical outcomes in certain patient populations.28 Although the optimal target range for inpatient glycemic control has not yet been defined, these studies support the goal of metabolic control for hospital patients. However, there are many barriers to achieving adequate glycemic control in the hospital, and blood glucoses in the hospital are often far from recommended targets.9, 10 One barrier appears to be the low priority given to glycemic control in the hospital. Hyperglycemia in the hospital is often ignored,11 and insulin regimens are often chosen for simplicity as opposed to effectiveness.12 Other barriers to glycemic control in the hospital include the physiologic effects (stress) of acute illness, and the frequent nutritional changes and interruptions that occur.

Most hyperglycemic patients on a general medicine unit are treated with subcutaneous insulin, but the optimal strategy for prescribing insulin in the hospital remains uncertain. A technical review of the literature on the management of diabetes in the hospital setting from 2004 recommends prescribing insulin in a way that mimics physiologic insulin secretion (ie, physiologic or basal‐bolus insulin).1 This approach has been promulgated by experts, but there has been very little research to support these recommendations. One small, randomized trial concluded that a basal‐bolus approach achieved better glycemic control than the use of sliding‐scale insulin alone,13 and 2 quality improvement studies using a before/after design have demonstrated improvements in glycemic control after the implementation of interventions designed to encourage physiologic insulin use.14, 15

In this study we hypothesized that a few simple interventions (education for physicians and nurses, and a standardized insulin order form) would lead to a higher rate of basal‐bolus insulin use and simultaneously improve glycemic control and patient safety.

Methods

Results

A total of 245 patients provided 1315 patient‐days. Patient demographics are shown in Table 2. The patients' weight, length‐of‐stay, and primary diagnoses were similar across the 3 groups. There was a higher percentage of males in the IG as compared to the HCG.

Table 3 shows the insulin regimens used in the different groups. The use of basal insulin was similar between groups. Congruent with the goals of the education session and the order set, patients in the IG were more likely to be treated with a combination of basal and nutritional insulin than patients in the other groups. Patients in the HCG were more likely to be treated with a premixed insulin than patients in the other groups. However, even when premixed insulin was categorized as a form of basal plus nutritional insulin and combined into a composite group with the combined basal and nutritional days, this type of regimen remained more common in the IG than in the HCG. The rate of sliding scale insulin use alone (ie, without any scheduled insulin) was similar in the 3 groups.

Other relevant measures are also shown in Table 3. The use of oral diabetes agents was similar in the 3 groups. The use of a nonoral feeding route (eg, tube feeding or parenteral nutrition) was infrequent.

A comparison of glycemic control in the three groups is shown in Table 4. In contrast to the CCG, patients in the IG experienced more days within the target glucose range (17% vs. 10.6%, P < 0.01), fewer days with severe hyperglycemia (48.3% vs. 59.2%, P < 0.01), and had a lower day‐weighted average blood glucose (195.9 vs. 212.6, P < 0.01). Compared to the HCG, patients in the IG experienced similar rates of hyperglycemia, but fewer hypoglycemic days (5.1% vs. 9.2%, P = 0.02).

The percentages of patients with severe hyperglycemia in each group are shown in Figure 1 by hospital day. Severe hyperglycemia was common, but there was a trend towards a decrease in the prevalence of severe hyperglycemia with increasing hospital days for all study groups, although it was consistently higher in the CCG than in the IG. Figure 2 shows the types of insulin regimens used by hospital day (composite for all groups). The use of basal plus nutritional insulin (the recommended regimen) increased gradually with increasing hospital days. When taken together, the information in both figures support the hypothesis that the use of the recommended insulin regimen may have contributed to the modest improvements in glycemic control seen in the IG.

Figure 1

Figure 2

In the final adjusted regression model, the intervention had a positive impact on glycemic control (Table 5). Subjects in the IG had a 72% increase in the odds of being in the target glucose range when compared to subjects in the CCG (P = 0.01). In addition, subjects in the IG had a 35% reduction in the odds of being severely hyperglycemic when compared to those in the CCG (P < 0.01). Finally, the odds ratio (OR) for being hypoglycemic among intervention subjects was 0.59 (P = 0.06) when compared to subjects in the CCG and 0.48 (P = 0.01) when compared to subjects in the HCG.

Discussion

In this study, we investigated the effects of a standardized insulin order set, coupled with physician and nurse education, on glycemic control in hyperglycemic hospitalized patients. These interventions were designed to encourage a standardized approach to the treatment of hyperglycemia in hospitalized patients, based on the principles of physiologic insulin use, as described above. Our data suggest that the interventions did, indeed, alter the way insulin was prescribed, as more patients in the IG received a combination of basal plus nutritional insulin (the recommended regimen) than in the other groups. These interventions were associated with improved glycemic outcomes in the IG as compared to the CCG. The IG experienced a higher percentage of days in the target range and a trend toward fewer hypoglycemic days than the CCG. Although the IG experienced a similar percentage of days in the target range, it had significantly fewer hypoglycemic days than the HCG.

It is useful to consider the results of our study in the context of 2 other similar studies performed by Schnipper et al.14 and Maynard et al.15 Although each of these 3 studies have different study designs, they are similar in intent (to test the effects of simple quality improvement interventions on glycemic control in the hospital) and results (all showed significant improvements in some aspect of glycemic control). In our study, and the study by Maynard et al.,15 the interventions also led to decreases in the rates of hypoglycemia, whereas Schnipper et al.14 observed no difference in hypoglycemia. Of interest, in each of the three studies the interventions were associated with an increase in the use of some type of scheduled insulin. In our study and the study from Schnipper et al.14 the baseline use of basal insulin was quite high, and the interventions were associated with a significant increase in the addition of nutritional insulin. In the Maynard et al.15 study, the baseline use of sliding scale insulin alone was prevalent, and the interventions resulted in an increase in the use of basal insulin. The results of these studies, taken together, prompt us to conclude that the interventions employed in these studies are likely to lead to more frequent prescription of scheduled (anticipatory) insulin, and a modest improvement in glycemic control, without an increase (and perhaps with a decrease) in hypoglycemia.

A few of our study results are unexpected, or difficult to explain. In contrast to the other studies discussed above, our interventions did not affect the frequency of the use of sliding‐scale insulin alone (without any scheduled insulin), which was similar in the 3 groups. Although the reason for this is uncertain, we hypothesize that the high baseline use of basal insulin in our institution, and the lack of a hard stop preventing the use of sliding scale insulin alone explain this finding. Also, it is difficult to explain why measures of hyperglycemia were similar between the IG and the HCG despite the fact that the HCG was less often treated with a combination of basal and nutritional insulin and more often treated with mixed insulin.

There are several different mechanisms by which the interventions might have resulted in improved glycemic control in the IG compared to CCG. Our data clearly shows that insulin was prescribed differently in the IG, and the more frequent use of a combination of scheduled basal and nutritional insulin might have contributed to the differences between the groups. However, the effects of our interventions clearly went beyond physician education into the realm of true process improvement and standardization. The standardized order form was designed to prompt physicians to use a basal‐bolus insulin regimen. The order form also created nursing expectations of how insulin should be ordered, and clarified the roles of the different insulins that were prescribed.

On the medication administration record, each insulin was labeled as basal insulin (to be given even when fasting) or nutritional insulin (to be given along with the meal). The nurses caring for the IG also attended an education program that reinforced the role of the nurse in the bedside management of insulin administration. Specifically, nurses were taught to assess the premeal blood glucose and the patient's nutritional situation before giving the nutritional insulin (ie, Does the patient have food available? Will he tolerate eating the food?). In situations where is was not clear if the patient would be able to tolerate the ordered nutrition, the order set empowered the nurse to give the nutritional insulin after the meal, and to reduce the dose to match the patient's actual intake. These interventions resulted in some fundamental improvements in the nursing process of delivering insulin to the patient, and these changes might have resulted in improvements via mechanisms that are difficult to directly measure. Since the same physicians cared for both the IG and the CCG, interventions other than physician education clearly contributed to the observed improvements in the IG.

This study was not a randomized study, and there could be important undetected differences between the groups. However, all of the patients were admitted to the General Medicine Inpatient Services and the comparison of the general patient demographics and primary diagnoses between the groups do not suggest major differences.

Although the improvements in glycemic control seen in this study were statistically significant, they were quantitatively modest. The rates of hyperglycemia seen in this study, on the other hand, are quite remarkable. Both the American Diabetes Association and the American College of Endocrinology have recommended that blood glucoses in hospitalized patients not exceed a maximum value of 180 mg/dL, but the day‐weighted average blood glucose in this study was above that for each group. Even in the IG, over 80% of all patient‐days included at least 1 blood glucose value outside of the target range. These data suggest that better strategies for achieving metabolic control in hospitalized patients are needed.

It is worth mentioning that our interventions were not aggressively enforced. While the use of the order set was mandatory for the IG, it was flexible enough to allow for substantial practice variation, especially with respect to the dose of insulin prescribed. Although the education sessions discussed the specifics of insulin dosing in hospitalized patients, the order form did not offer dosing guidelines. It is possible that our interventions may have had a larger impact if a starting dose of insulin had been specified on the form. Although the insulin order form prompted physicians to act, there were no forced functions. Also, not all house staff attended the education sessions for physicians, and there was no feedback provided to physicians related to how they might improve their adherence to the recommendations presented in the educational module. Therefore, it is likely that more aggressive interventions could have led to greater changes in physician practice.

In conclusion, this study demonstrates that interventions including physician and nurse education and a standardized insulin order set can lead to improvement in glycemic control and patient safety in hospitalized patients treated with subcutaneous insulin. However, the observed improvements are modest, and poor metabolic control remains common, despite these interventions. These data suggest that standardization of the process of ordering and delivering subcutaneous insulin in the hospital may lead to a reduction in both hyperglycemia and hypoglycemia. However, it is clear that the interventions used in this study were not potent enough to achieve the recommended glycemic targets for the majority of patients. Additional research is needed to determine the best strategy for achieving safe and effective metabolic control in hospitalized, hyperglycemic, noncritically ill patients.