The impact of postgraduate training on USMLE® step 3® and its computer-based case simulation component.

BACKGROUND: The United States Medical Licensing Examination® (USMLE®) Step 3® examination is a computer-based examination composed of multiple choice questions (MCQ) and computer-based case simulations (CCS). The CCS portion of Step 3 is unique in that examinees are exposed to interactive patient-care simulations. OBJECTIVE: The purpose of the following study is to investigate whether the type and length of examinees' postgraduate training impacts performance on the CCS component of Step 3, consistent with previous research on overall Step 3 performance. DESIGN: Retrospective cohort study PARTICIPANTS: Medical school graduates from U.S. and Canadian institutions completing Step 3 for the first time between March 2007 and December 2009 (n = 40,588). METHODS: Post-graduate training was classified as either broadly focused for general areas of medicine (e.g. pediatrics) or narrowly focused for specific areas of medicine (e.g. radiology). A three-way between-subjects MANOVA was utilized to test for main and interaction effects on Step 3 and CCS scores between the demographic characteristics of the sample and type of residency. Additionally, to examine the impact of postgraduate training, CCS scores were regressed on Step 1 and Step 2 Clinical Knowledge (CK) scores. Residuals from the resulting regressions were plotted. RESULTS: There was a significant difference in CCS scores between broadly focused (μ = 216, σ = 17) and narrowly focused (μ=211, σ = 16) residencies (p < 0.001). Examinees in broadly focused residencies performed better overall and as length of training increased, compared to examinees in narrowly focused residencies. Predictors of Step 1 and Step 2 CK explained 55% of overall Step 3 variability and 9% of CCS score variability. CONCLUSIONS: Factors influencing performance on the CCS component may be similar to those affecting Step 3 overall. Findings are supportive of the validity of the Step 3 program and may be useful to program directors and residents in considering readiness to take this examination.