The Effects of Inpatient Specialty Consultations on Health and Utilization Outcomes

Objective: To estimate the effects of specialty consultations on health and utilization outcomes among general medicine admissions. Background: Specialist physicians are frequently consulted in the inpatient setting to obtain additional expertise or get access to specific treatments. However, the effects of these consults have not been rigorously studied. Methods: In this quasi-experimental study, I analyzed the effects of an infectious disease, cardiology, or nephrology consult that occurred within 24 hours of admission. To address patient-level confounding, consultant team workload, defined as consult orders per provider, served as an instrumental variable for consult receipt. I identified general medicine admissions from 3 teaching hospitals in Pennsylvania using electronic health record data spanning March 2017 to August 2024. Primary outcomes were length of stay and readmission, mortality, and specialty outpatient visit within 30 days of discharge. Results: Among admissions whose consult probability varied by consultant workload, a specialty consult decreased 30-day readmission by 29.8 percentage points (pp) (95% CI: −52.0 to −7.7 pp) and increased 30-day outpatient visit by 18.6 pp (95% CI: 7.3–29.9 pp). The decrease in the probability of readmission was primarily driven by infectious disease consults and patients who had not received a specialty consult in the past year. Consults had no significant effects on mortality or length of stay. Conclusions: Specialty consults may reduce readmissions and improve continuity of care without increasing inpatient utilization on average.