Factors Associated with Higher NBME Practice and Shelf Exam Scores in the Internal Medicine Clerkship

National Board of Medical Examiners subject examination success is a priority for medical students. Many clerkships integrate subject examination scores into final clerkship grades, which may influence honors. Investigation of both student- and clerkship-related factors which may affect examination scores is essential to clerkship directors' coaching for study.

This was a single-center, cohort, correlational study conducted on the main campus at a large university-based teaching hospital, which enrolled 126 students in the Internal Medicine Clerkship during the studied year. The primary outcomes of interest were factors on the mid- and end-of-clerkship surveys associated with practice and final subject examination scores.

The authors screened potential predictor variables using univariate regression analyses and retained variables associated with NBME-SE score at 0.10 level. Seven variables met the 0.10 threshold. For every 1 standard deviation increase in UWorld questions completed (SD = 583.9; average 412 questions) by mid-clerkship, NBME-SE exam scores increased by 1.51 points (95%CI 0.22, 2.80). For every 1 standard deviation increase in UWorld (SD = 319.9; average 877 questions) completed by the end-of-clerkship, the NBME-SE exam score rose by 1.30 points (95%CI 0.01, 2.59).

The most notable finding was the usage of UWorld question bank, which resulted in an increase of 6.69 points on the subject examination score. Additionally, students who completed more questions had higher scores, both at the mid and end of clerkship. This suggested we could council clerkship students that the order of their rotations, attendings, self-evaluations, and methods of study were unlikely to affect performance, though routine use of a student-related factor (a question bank) was likely to improve their subject examination score. Given ongoing use of clerkship subject examination tests is anticipated, additional research on factors that may increase student scores is critical.