Purpose
Stress resilience and empathy are essential non-cognitive attributes in medical education, particularly in surgical training. However, the extent to which changes in these traits over time impact objective measures of clinical performance, such as percentile performance on the NBME surgery shelf examination, remains unclear. This study explores how longitudinal trajectories of stress resilience and empathy, alongside USMLE Step 1 performance, predict success in the surgery clerkship.

Methods
A longitudinal cohort of 304 medical students was assessed at three phases of training. Stress resilience and empathy were measured using validated self-report Likert scales ranging from 0 to 15 for stress and 0 to 32 for empathy. Changes were analyzed using paired t-tests. USMLE Step 1 scores (n=132) and NBME surgery shelf exam percentile scores (n=245) were collected. Multivariate analyses were used to evaluate the predictive value of stress, empathy, and Step 1 scores on surgery shelf exam performance.

Results
Stress resilience improved over time, with significant increases from Phase 1 to Phase 2 (+0.39 pts, p=0.009) followed by a decline from Phase 2 to Phase 3 (–1.74 pts, p<0.001). Overall, stress decreased from Phase 1 to Phase 3 (–1.36 pts, p<0.001). Empathy decreased significantly between Phase 1 and Phase 2 (–0.72 pts, p=0.045), then plateaued. Step 1 performance was the strongest independent predictor of percentile scores on the NBME surgery shelf exam. Neither changes in stress resilience nor empathy showed a significant relationship with shelf performance after accounting for academic achievement.

Conclusion
Although stress resilience improves and empathy declines during medical training, only academic performance, as measured by Step 1, predicts success on the NBME surgery shelf exam. These findings underscore the dominant role of cognitive metrics in clinical performance evaluations.