Predicting Success: A Comparative Analysis of Student Performance on the Surgical Clerkship and the NBME Surgery Subject Exam

Abstract

Background: The National Board of Medical Examiners Surgery Shelf Exam (SSE) is a well established terminal measure of student medical knowledge. No study has explored the correlation between intraclerkship quizzes and shelf exam performance.

Methods: Weekly quiz and NBME scores were collected from 156 third-year students who participated in a 12-week surgical clerkship from 2015-2017. Kruskal Wallis, Wilcoxon Rank Sum, and linear regression analysis was completed.

Results: Trauma/Burns, Esophagus/Anorectal, and Wound/ICU quiz content corresponded with increased NBME performance with β-coefficients of 1.57 (p<0.001), 1.42 (p<0.001),1.38 (p<0.001), respectively. Wound/ICU and Cardiac/Vascular content corresponded with decreased likelihood of scoring <70 points on the NBME (OR: 0.75 (p=0.03), and 0.68 (p=0.02)). Aggregate quiz scores stratified by academic block were 67 (IQR 64-69.5), 77 (IQR 74.5-80),76.5 (IQR of 67-89.5), 83 (IQR of 76-85) corresponding to academic blocks 1, 2, 3, and 4, respectively (P<0.001).

Conclusion: Modeling NBME outcomes as a function of weekly quizzes taken during a 12-week surgery clerkship is a viable concept. This can allow surgical educators to intervene and assist students at risk for failing the SSE.

Keywords: NBME, Surgery, Shelf, Clerkship, Performance, Education