Relationship Between Performance on the NBME Comprehensive Basic Sciences Self-Assessment and USMLE Step 1 for U.S. and Canadian Medical School Students

Abstract

This study examined the relationship between performance on the National Board of Medical Examiners Comprehensive Basic Science Self-Assessment (CBSSA) and performance on United States Medical Licensing Examination Step 1. The study included 12,224 U.S. and Canadian medical school students who took CBSSA prior to their first Step 1 attempt. Linear and logistic regression analyses investigated the relationship between CBSSA performance and performance on Step 1, and how that relationship was related to interval between exams. CBSSA scores explained 67% of the variation in first Step 1 scores as the sole predictor variable and 69% of the variation when time between CBSSA attempt and first Step 1 attempt was also included as a predictor. Logistic regression results showed that examinees with low scores on CBSSA were at higher risk of failing their first Step 1 attempt. Results suggest that CBSSA can provide students with a realistic self-assessment of their readiness to take Step 1.