What Is the Effect of Taking a Practice Surgery Shelf Exam on Final Shelf Exam Score?

Objective: The purpose of this study was threefold. The first objective was to determine the effect of a practice surgical shelf exam taken during the surgery clerkship on NBME surgical shelf exam score at the conclusion of the clerkship. The second was to determine the effect of the practice shelf exam on USMLE Step 2 CK exam score. The last objective was to assess the value of a practice shelf exam score in predicting final surgical shelf exam score. Methods: Students from three classes within BSOM were separated into a group of students who took a practice shelf exam during their surgical clerkship and another group of students who did not. Independent measures t-tests were used to compare the GPA, Step 1 scores, Step 2 CK scores, and NBME surgical shelf scores of the two groups. Linear regression analysis was used to determine the correlation and R2 value between practice shelf exam scores and final shelf exam scores. Results: There was a significant difference in Step 1 scores (p=0.046) for the two groups. There was no significant difference in GPA (p=0.765), mean scores on the final shelf exam Pohlman 2 (p=0.233), or Step 2 CK scores (p=0.099) of the two groups. The correlation between practice exam scores and NBME shelf exam scores was 0.560 with an R2 value of 0.313. This showed a moderate correlation between practice and NBME shelf exam scores with a limited amount of the variance in final shelf exam score accounted for by practice shelf exam score