Difficulty and discrimination indices of multiple-choice examination items in a college of pharmacy therapeutics and pathophysiology course sequence

Abstract

Abstract Objective The purpose of this study was to identify differences in difficulty and discrimination among multiple-choice examination items with regard to format and content in pharmacy therapeutics and pathophysiology (TP) courses. Methods Items from a TP course sequence were categorized by format and content by a faculty committee using the Delphi technique. Difficulty was not normally distributed; therefore, a logit transformation was employed. Difficulty and discrimination were analysed using one-way analysis of variance, with post hoc Bonferroni correction for pairs, to detect differences. Key findings A total of 516 items were included, with approximately 233 students answering each item. Case-based items were statistically more difficult than Standard (P = 0.0007) or Statement items (P = 0.001) and more discriminatory than Standard items (P = 0.015). Dosing items were more difficult (P = 0.013) and discriminating (P = 0.02) than therapeutics items. Conclusions Case-based items appear to have been more difficult than other items and may provide greater discrimination than Standard items.