Relative United States Medical Licensing Examination (USMLE) Performance by Specialty Is Not a Predictor of Board Exam Pass Rate: The Case of Diagnostic Radiology

Introduction In 2010 diagnostic radiology (DR) changed the board certification process for residents using the new Core exam. However, there is not a standardized way to evaluate DR residency graduates. With no specific target pass rate for the exam, the "appropriate" pass rate has remained a debated topic among the field. In this paper, the board certification exam passage rates of DR are compared to other medical specialties to assess the standardization method of the American Board of Radiology (ABR) and serve as basis for additional specialties considering changes to their board exam structure. Methods Performance on the United States Medical Licensing Examination (USMLE) was obtained from the National Resident Matching Program (NRMP) and San Francisco match. Boards passage rates were analyzed using data from the American Board of Medical Specialties. USMLE and board exam passage rates were averaged and ranked, and statistical analysis was conducted using Stata (College Station, TX). Results DR performance on USMLE Step 1 has increased at the lowest rate (0.563 points/year) since 2005 and anesthesiology performance has increased at the greatest rate (1.313 points/year). Residents matching from US allopathic medical schools during the 2010 and 2012 years had DR oral board exams with USMLE 1 averages of 232 and 235, respectively. First-time pass rate for the first Core exam was 87% and the overall pass rate since the first Core exam has been 88.54%. The Spearman rho coefficient for specialty ranks of board passage rate and USMLE 1 was 0.0679 (p = 0.8101). The Spearman rho coefficient for board passage rate and USMLE 2 CK was 0.1430 (p = 0.6257). The Spearman rho coefficient for USMLE 1 and USMLE 2 CK was 0.8317 (p = 0.0002). Conclusions Specialty board pass rates have not increased in concert with improved trainee performance on the USMLE. USMLE performance among those matching in diagnostic radiology has increased, ABR board exam passage rate has decreased. ABR determines passing thresholds to the relative performance of examinees rather than using a criterion referenced Angoff standard.