Predictors of Performance on the United States Medical Licensing Examination Step 2 Clinical Knowledge: A Systematic Literature Review

In February 2020, the governing bodies of the United States Medical Licensing Examination (USMLE) announced the decision to change Step 1 score reporting from a three-digit system to pass/fail designation. Previous studies theorized that Step 2 Clinical Knowledge (CK) will become the numerical standard by which residency directors can quickly sort through program applicants. The goal of this study is to review prior research and identify significant factors associated with Step 2 CK outcomes. A systematic literature search on PubMed, Web of Science, Scopus, and ERIC that included articles published between 2005 and 2015 was conducted using the keywords “USMLE,” “Step 2 CK,” “score,” “success,” and “predictors.” After screening the initial search yield of 3,239 articles, 52 articles were included for this review. Positively correlated factors included Step 1 score, clinical block grades, Comprehensive Clinical Science Self-Assessment (CCSSA), Comprehensive Clinical Science Examination (CCSE), and volunteerism. Factors such as clerkship sequence and pass/fail grading failed to correlate with Step 2 CK. Medical College Admission Test (MCAT) score (p < 0.01) and undergraduate grade point average (GPA) (p = 0.01) positively correlated, while age displayed a negative correlation. Additionally, females typically scored higher on Step 2 CK than their male peers. The study findings suggest that continuous learning and academic success throughout medical school positively influence eventual Step 2 CK scoring. Performance on USMLE practice examinations, Step 1, and clinical evaluations serve as positive predictors for Step 2 CK scores. Interestingly, changing answers and spending more time on each question during the examination were associated with higher scores.