Background: It is not known whether differences exist between the use of inpatient resources by family medicine and internal medicine physicians when patient demographic and complexity variables are statistically controlled.
Methods: The study population was all patients in 13 higher volume diagnosis-related groups (DRGs) discharged from the family medicine (n = 306) and internal medicine services (n = 2374) of the University of Cincinnati Hospital during 1985 and 1986. The dependent variables were length of stay and inpatient readmission within 2 weeks. Stratification by DRGs was used to control for the effects of age and case mix on these variables.
Results: With the exception of findings regarding one DRG, the results do not indicate that differences exist in average length of stay between patients of family medicine and internal medicine physicians after adjustment for other variables. Furthermore, almost all of the explained variance in length of stay was attributed to patient complexity and not to physician specialty or patient race or sex. For all discharges, the proportion of patients readmitted within 2 weeks was about 4% higher for the internal medicine service. However, multivariate analysis did not support the importance of physician specialty (family medicine or internal medicine) as a predictor of whether readmission occurred within 2 weeks.
Conclusions: General indicators of resource use (such as length of stay or readmission occurrence) without adjustment for patient case mix, demographics, and complexity are inadequate for comparison of health care providers. Further research regarding interspecialty differences should use longitudinal data from large populations, which would permit more detailed examination of resource utilization.