Psychometric Characteristics of Oral Pathology Test Items in the Dental Hygiene Curriculum—A Longitudinal Analysis

Abstract

As the landscape of oral healthcare and the delivery of services continue to undergo change, the dental hygienist plays an increasing role in assisting dentists with oral diagnosis and preventive strategies. Hence, the dental hygiene curriculum standards require biomedical science instructions, including general and oral pathology. Student learning and cognitive competencies are often measured using multiple-choice questions (MCQs). The objectives of this study were to perform a longitudinal analysis of test items and to evaluate their relation to the absolute grades of the oral pathology course in the dental hygiene curriculum. A total of 1033 MCQs covering different concepts of oral pathology administered from 2015 through 2019 were analyzed for difficulty and discriminatory indices, and the differences between the years were determined by one-way ANOVA. Test reliability as determined by the average KR-20 value was 0.7 or higher for each exam. The mean difficulty index for all exams was 0.73 +/− 0.05, and that of the discriminatory index was 0.33 +/− 0.05. Wide variations were observed in the discriminatory indices of test items with approximately the same difficulty index, as well as in the grade distribution in each cohort. Furthermore, longitudinal data analyses identified low achieving cohorts amongst the groups evaluated for the same knowledge domain, taught with the same instruction, and using similar test tools. This suggest that comparative analyses of tests could offer feedback not only on student learning attributes, but also potentially on the admission processes to the dental hygiene program.