Is There a Correlation Between Comprehensive Basic Science Examination and United States Medical Licensure Examination Step 1 Performance Among Oral and Maxillofacial Surgery Residents?

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 Licensure Examination (USMLE) Step 1 performance. The purpose of this study was to answer the following question: Is there a correlation between the OMS applicant's CBSE score and his or her later USMLE Step 1 score? Materials and Methods: We e-mailed 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: Of 45 United States–based, dual-degree OMS residency programs, 23 (51%) enrolled in the study, including data for 152 residents from 2012 to 2018. The mean CBSE score was 71 (range, 47 to 99). The mean USMLE Step 1 score was 220 (range, 177 to 266). The Pearson correlation coefficient for the relationship between the CBSE and USMLE Step 1 scores 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. Of the 50 residents (33%) with a translated CBSE score below the passing level, 94% passed the 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). Conclusions: Although no statistically significant difference in the USMLE Step 1 pass rates was found between OMS residents with a translated passing CBSE score and those with a translated failing CBSE score, a weak positive correlation was noted between CBSE and USMLE Step 1 scores. These data do not support the use of a certain cutoff CBSE score for OMS applications by OMS program directors, especially as it pertains to interview offers.