Is There a Correlation Between CBSE and USMLE Step 1 Performance Among OMS Residents

Abstract Purpose Oral and maxillofacial surgery (OMS) applicant Comprehensive Basic Science Examination (CBSE) scores are scrutinized by residency programs and medical schools because of their perceived predictive value for United States Medical Licensing Exam (USMLE) Step 1 performance. The purpose of this study is to answer the question, “Is there a correlation between OMS applicant CBSE score and their later USMLE Step 1 score?” Methods The authors emailed all current 45 dual degree OMS residency programs to request participation in the study. Participating programs submitted residents’ CBSE scores and USMLE Step 1 scores. Results 23 of 45 (51%) US-based, dual degree OMS residency programs enrolled in the study, including data for 152 residents from 2014 to 2018. The mean CBSE score was 71 (range 47 – 99). The mean USMLE Step 1 score was 220 (range 177 – 266). The Pearson’s correlation coefficient between the relationship of CBSE and USMLE Step 1 was 0.36. The overall USMLE pass rate was 97%. On the USMLE Step 1, OMS residents outperformed their translated CBSE score by an average of 15 points. Out of the 50 (33%) residents with a translated CBSE score below the passing level, 94% of them passed USMLE Step 1. Residents who had a translated passing CBSE score outscored residents with a translated failing score by 14 points when taking the USMLE Step 1 (225 vs 211, respectively). Conclusions Although there was no statistically significant difference in the USMLE Step 1 pass rates between OMS residents with a translated passing CBSE score compared to those with a translated failing CBSE score, there was a weak positive correlation between CBSE score and USMLE Step1 scores. These data do not support the use of a certain cut-off CBSE score for OMS applications by OMS program directors, especially as it pertains to interview offers.