Association between patient-surgeon gender concordance and mortality after surgery in the United States: retrospective observational study

OBJECTIVE: To determine whether patient-surgeon gender concordance is associated with mortality of patients after surgery in the United States. DESIGN: Retrospective observational study. SETTING: Acute care hospitals in the US. PARTICIPANTS: 100% of Medicare fee-for-service beneficiaries aged 65-99 years who had one of 14 major elective or non-elective (emergent or urgent) surgeries in 2016-19. MAIN OUTCOME MEASURES: Mortality after surgery, defined as death within 30 days of the operation. Adjustments were made for patient and surgeon characteristics and hospital fixed effects (effectively comparing patients within the same hospital). RESULTS: Among 2 902 756 patients who had surgery, 1 287 845 (44.4%) had operations done by surgeons of the same gender (1 201 712 (41.4%) male patient and male surgeon, 86 133 (3.0%) female patient and female surgeon) and 1 614 911 (55.6%) were by surgeons of different gender (52 944 (1.8%) male patient and female surgeon, 1 561 967 (53.8%) female patient and male surgeon). Adjusted 30 day mortality after surgery was 2.0% for male patient-male surgeon dyads, 1.7% for male patient-female surgeon dyads, 1.5% for female patient-male surgeon dyads, and 1.3% for female patient-female surgeon dyads. Patient-surgeon gender concordance was associated with a slightly lower mortality for female patients (adjusted risk difference -0.2 percentage point (95% confidence interval -0.3 to -0.1); P<0.001), but a higher mortality for male patients (0.3 (0.2 to 0.5); P<0.001) for elective procedures, although the difference was small and not clinically meaningful. No evidence suggests that operative mortality differed by patient-surgeon gender concordance for non-elective procedures. CONCLUSIONS: Post-operative mortality rates were similar (ie, the difference was small and not clinically meaningful) among the four types of patient-surgeon gender dyads.