Results
Records review identified 17,294 adult patient hospitalizations determined by Crimson to have a medical (non-surgical, non-obstetrical) APR-DRG code as the final principal diagnosis. We excluded 15 expanded PA and 11 conventional hospitalizations that fell under APR-DRG code 956 “ungroupable.” Exclusion for referral bias resulted in the removal of 304 hospitalizations, 207 (3.03%) from the expanded PA group and 97 (0.92%) from the conventional group. These excluded hospitalizations came from 2 APR-DRG codes, urinary stones (code 465) and “other kidney and urinary tract diagnoses” (code 468). This left 6612 hospitalizations in the expanded PA group and 10,352 in the conventional group.
Characteristics of the study population are summarized in Table 3 . The expanded PA group saw a greater proportion of Medicare patients and lower proportion of Medicaid, self-pay, and privately insured patients ( P < 0.001). The mean APR-DRG ROM was slightly higher ( P = 0.01) and the mean APR-DRG SOI was slightly lower ( P = 0.02) in the expanded PA group, and their patients were older ( P < 0.001). The 10 most common diagnoses cared for by both groups were sepsis (APR-DRG 720), heart failure (194), chronic obstructive pulmonary disease (140), pneumonia (139), kidney and urinary tract infections (463), cardiac arrhythmia (201), ischemic stroke (45), cellulitis and other skin infections (383), renal failure (460), other digestive system diagnoses (254). These diagnoses comprised 2454 (37.1%) and 3975 (38.4%) cases in the expanded PA and conventional groups, respectively.Charge capture data for both groups was used to determine the proportion of encounters rendered by each provider type or combination. In the expanded PA group, 35.73% of visits (10,241 of 28,663) were conducted by a PA, and 64.27% were conducted by a physician or by a PA with a billable physician “co-visit.” In the conventional group, 5.89% of visits (2938 of 49,883) were conducted by a PA, and 94.11% were conducted by a physician only or by a PA with a billable physician “co-visit”.
Readmissions
Overall, 929 of 6612 (14.05%) and 1417 of 10,352 (13.69%) patients were readmitted after being discharged by the expanded PA and conventional groups, respectively. After multivariate analysis, there was no statistically significant difference in odds of readmission between the groups (OR for conventional group, 0.95 [95% CI, 0.87–1.04]; P = 0.27).
Inpatient Mortality
Unadjusted inpatient mortality for the expanded PA group was 1.30% and 0.99% for the conventional group. After multivariate analysis, there was no statistically significant difference in odds of in-hospital mortality between the groups (OR for conventional group, 0.89 [95% CI, 0.66–1.19]; P = 0.42).
Patient Charges
The unadjusted mean patient charge in the expanded PA group was $7822 ± $7755 and in the conventional group mean patient charge was $8307 ± 10,034. Multivariate analysis found significantly lower adjusted patient charges in the expanded PA group relative to the conventional group (3.52% lower in the expanded PA group [95% CI, 2.66%–4.39%, P < 0.001). When comparing a “standard” patient who was between 80–89 and had Medicare insurance and an SOI of “major,” the cost of care was $2644 in the expanded PA group vs $2724 in the conventional group.