Impact of 24-hour call frequency (every 3rd vs every 4th day) on academic performance of general surgery residents.

INTRODUCTION: In Mexico, where surgical residents receive formal academic grades, the effect of on-call schedules on educational outcomes has not been previously evaluated. METHODS: This retrospective cohort study analyzed general surgery residents at a tertiary academic center. A structural change in 2020 created two cohorts: an every-third-day (Q3) schedule with 24-h shifts (2012-2015) and an every-fourth-day (Q4) schedule with 24-h shifts (2017-2021). Academic performance was obtained from institutional records and compared using appropriate statistical tests. RESULTS: Sixty-three residents were included (Q3: n = 33; Q4: n = 30). Q4 residents achieved higher median scores in core curriculum (88.9 vs. 85.5, P < 0.001) and overall assessments (90.96 vs. 89.20, P < 0.001), while Q3 residents had slightly higher clinical activity scores (93.00 vs. 91.57, P < 0.001). CONCLUSION: Less frequent on-call schedules were associated with improved academic performance.