Comparison of hospitalists and nonhospitalists in inpatient length of stay adjusting for patient and physician characteristics

OBJECTIVE: To determine the independent effect of hospitalist status upon inpatient length of stay after controlling for case mix, as well as patient-level and provider-level variables such as age, years since physician medical school graduation, and volume status of provider. DESIGN: Observational retrospective cohort study employing a hierarchical random intercept logistic regression model. SETTING: Tertiary-care teaching hospital. PATIENTS: All admissions during 2001 to the department of medicine not sent initially to the medical intensive care unit or coronary care unit. MEASUREMENTS: Observed length of stay (LOS) compared to principle diagnosis related group (DRG)-specific mean LOS for hospitalist and nonhospitalist patients adjusting for patient age, gender, years since physician graduation from medical school, and physician volume status. MAIN RESULTS: The 9 hospitalists discharged 2,027 patients while the nonhospitalists discharged 9,361 patients. On average, hospitalist patients were younger, 63.3 versus 73.3 years (P < .0001). Hospitalists were more recently graduated from medical school, 13.8 versus 22.5 years (P= .02). Each year of patient age was found to increase the likelihood of an above average LOS (odds ratio [OR], 1.01; 95% confidence interval [CI], 1.01 to 1.02; P < .001). In unadjusted analysis, hospitalists were less likely to have an above average LOS (OR, 0.51; 95% CI, 0.28 to 0.93; P= .03). Adjustment for effects of patient age and gender, physician gender, years since medical school graduation, and quintile of physician admission volume did not appreciably change the point estimate that hospitalist patients remained less likely to have above average LOS (OR, 0.60; 95% CI, 0.32 to 1.11; P= .11). CONCLUSIONS: For a given principle DRG, hospitalist patients were less likely to exceed the average LOS than were nonhospitalist patients. This effect was rather large, in that hospitalist status reduced the likelihood of above average LOS by about 49%. Adjustment for patient age, years since physician graduation, and admission volume did not significantly alter this finding. Further research should focus on identifying specific practices that account for hospitalism's effects.