Physician Sex and Outcomes Among Hospitalized Patients

Importance: Prior studies have shown that patients treated by female physicians experience better outcomes than those treated by male physicians, but evidence has often focused on surgical populations. The association between physician sex and outcomes among hospitalized medical patients across different health care systems remains less well understood. Objective: To examine associations between physician sex and care outcomes among hospitalized medical patients admitted with common medical diagnoses in Ontario, Canada. Design, Setting, and Participants: This population-based, retrospective cohort study was conducted between January 1, 2008, and December 31, 2022, among inpatients aged 18 years or older admitted with 1 of 7 common acute medical conditions in Ontario, Canada. Data were analyzed from August 16, 2024, to July 13, 2026. Exposure: Physician sex, defined in 2 ways: binary sex of the most responsible physician during hospital admission and proportion of in-hospital days managed by a female physician. Main Outcomes and Measures: Primary outcomes were 30-day mortality and hospital readmission. Secondary outcomes included 90-day and 1-year mortality and readmission and index hospital length of stay. Multivariable generalized estimating equations were used to calculate adjusted odds ratios (AORs) accounting for patient-, physician-, and hospital-level covariates. Results: The cohort included 958 150 patients (54.3% male; median age, 74 years [IQR, 62-83 years]). After adjustment, care by female compared with male physicians was associated with lower 30-day mortality (12.3% [95% CI, 7.2%-21.1%] vs 13.7% [95% CI, 7.9%-23.8%]; AOR, 0.88 [95% CI, 0.85-0.91]) and hospital readmission (18.6% [95% CI, 17.0%-20.2%] vs 18.9% [95% CI, 17.3%-20.5%]; AOR, 0.98 [95% CI, 0.97-1.00]). When physician sex was operationalized as proportion of in-hospital days managed by a female physician (per 10% increment), greater exposure to care by a female physician was associated with lower 30-day mortality (AOR, 0.93; 95% CI, 0.90-0.97) and readmission (AOR, 0.99; 95% CI, 0.98-0.99). Conclusions and Relevance: In this cohort study of hospitalized medical patients, those cared for by female physicians experienced lower 30-day mortality compared with those treated by male physicians. These findings warrant further investigation to elucidate underlying mechanisms and potential differences in physician practice patterns.