Examining the validity of chiropractic grade point averages for predicting National Board of Chiropractic Examiners Part I exam scores

Abstract

The main objective of this study was to evaluate the validity of grade point average (GPA) for predicting the National Board of Chiropractic Examiners (NBCE) Part I exam scores using chiropractic GPA. Data were collected during the January 2019 computer-based testing administration of the NBCE's Part I exam. The sample size was n = 2278 of test takers from 18 domestic and 4 international chiropractic educational institutions. Six regression models were developed and tested to predict the Part I domain scores from chiropractic GPA while controlling for self-reported demographic variables. Residuals from the models were disaggregated by pre-chiropractic GPA. Chiropractic GPA revealed a positive, statistically significant correlation with sex. The chiropractic GPA was found to be a significant predictor of the Part I domain scores. A different perspective was obtained when residuals (observed minus predicted) were collected and split by the pre-chiropractic GPA. Very good students tended to be underpredicted, while other students were overpredicted. This study builds on the cascading evidence from educational literature by providing additional results suggesting that undergraduate (prechiropractic) GPA as well as the GPA obtained in doctor of chiropractic programs are related to the future performance on the NBCE Part I exam. The results provide a first glance at the connection between the standardized test scores, which are often used for instructors' and institutional evaluation and the GPA obtained in a doctor of chiropractic program.