Purpose: To examine whether demographic differences exist in United States Medical Licensing Examination (USMLE) scores and the extent to which any differences are explained by students' prior academic achievement.
Method: The authors completed hierarchical linear modeling of data for U.S. and Canadian allopathic and osteopathic medical graduates testing on USMLE Step 1 during or after 2010, and completing USMLE Step 3 by 2015. Main outcome measures were computer-based USMLE examinations: Step 1, Step 2 Clinical Knowledge, and Step 3. Test-taker characteristics included sex, self-identified race, U.S. citizenship status, English as a second language, and age at first Step 1 attempt. Covariates included composite Medical College Admission Test (MCAT) scores, undergraduate grade point average (GPA), and previous USMLE scores.
Results: A total of 45,154 examinees from 172 medical schools met the inclusion criteria. The sample was 67% white and 48% female; 3.7% non-U.S. citizens; and 7.4% with English as a second language. Hierarchical linear models examined demographic variables with and without covariates including MCAT scores and GPA. All Step examinations showed significant differences by gender after adding covariates, varying by Step. Racial differences were observed for each Step, attenuated by the addition of covariates.
Conclusions: Demographic differences in USMLE performance were tempered by previous examination performance and undergraduate performance. Additional research is required to identify factors that contribute to demographic differences, can aid educators' identification of students who would benefit from assistance preparing for USMLE, and can assist residency program directors in assessing performance measures while meeting diversity goals.