Smaller steps, bigger gains: using nested EPAs to capture progressive operative competence

Purpose Competency-based medical education frameworks are transforming surgical training, but existing assessment tools may not detect incremental intraoperative skill acquisition in junior residents. To provide a granular assessment of progressive skill acquisition, we developed 10 nested Entrustable Professional Activities (EPAs), discrete surgical tasks embedded within American Board of Surgery core 18 General Surgery EPAs. We hypothesized that residents would earn higher entrustment scores on nested EPAs than core EPAs, reflecting earlier detection of operative competency. Methods We conducted a single-center retrospective analysis of core and nested EPA assessments for all clinical general surgery residents during two academic years (June 2024–June 2026). EPAs were evaluated on the ABS 4-point entrustment-supervision scale. Residents were grouped by clinical year (PGY1–5). Median core and nested EPA scores were compared using the Wilcoxon signed-rank test, with secondary analysis examining paired median differences (nested minus core scores). Results Sixty-eight residents had 1811 and 161 assessments for core EPAs and nested EPAs, respectively. Nested EPA scores demonstrated an earlier upward trajectory and increased over each year increment from PGY1 to PGY4, whereas core EPA scores only increased between PGY2–PGY3 and PGY4–PGY5. Paired median nested EPA scores exceeded core EPA scores for PGY1–4, with significant differences at PGY1 ( p = 0.016) and PGY4 ( p = 0.046). Conclusions Nested EPAs capture earlier intraoperative progression than core EPAs, particularly for junior trainees. As a complement to existing competency-based assessment frameworks, nested EPAs may facilitate earlier identification of trainees needing additional support while providing residents with meaningful markers of operative progress.