Using the NBME self-assessments to project performance on USMLE Step 1 and Step 2: impact of test administration conditions

This study examined the extent to which performance on the NBME(R) Comprehensive Basic Science Self-Assessment (CBSSA) and NBME Comprehensive Clinical Science Self-Assessment (CCSSA) can be used to project performance on USMLE Step 1 and Step 2 examinations, respectively. Subjects were 1,156 U.S./Canadian medical students who took either (1) the CBSSA and Step 1, or (2) the CCSSA and Step 2, between April 2003 and January 2004. Regression analyses examined the relationship between each self-assessment and corresponding USMLE Step as a function of test administration conditions. The CBSSA explained 62% of the variation in Step 1 scores, while the CCSSA explained 56% of Step 2 score variation. In both samples, Standard-Paced conditions produced better estimates of future Step performance than Self-Paced ones. Results indicate that self-assessment examinations provide an accurate basis for predicting performance on the associated Step with some variation in predictive accuracy across test administration conditions.