Finally, negative values indicate students with lower exam scores answered the question correctly compared to students who answered incorrectly. (Table 4). The Health Professions Division Testing Center provides difficulty indices and item discrimination as standard reports for every exam that it scores. The difficulty and discrimination indices of all assessment items were analysed for differences
by format (i.e. Standard, Case-based, Statement, K-type and True/False) and content (i.e. therapeutics, pathophysiology, dosing). The difficulty index was not EPZ5676 datasheet normally distributed; therefore, a logit transformation was employed. The discrimination index was normally distributed. One-way analysis of variance (ANOVA) with post hoc Bonferroni correction for pairs to detect differences in mean difficulty or discrimination were employed. The format*content interaction was examined using two-way ANOVA and post hoc Bonferroni correction for pairs. A significance level of P = 0.05 was used for all comparisons. A total of 586 assessment items developed by approximately 20 faculty members were retrieved and classified by the faculty Delphi committee. Fifty questions were excluded due to lack of item response
data (i.e. aggregate statistics not available) and 20 others were excluded due to multiple correct responses (e.g. double-keyed). As a result, 516 items were included in the final analysis (Table 1). On average, each item was answered by approximately Inositol monophosphatase 1 check details 233 students and all items (except True/False) contained four choices. There were 219 Case-based items, 182 Standard items, 91 Statement items, 14 K-type items and 10 True/False items. The rank order of increasing difficulty by format was True/False (0.92; 95% confidence interval (CI) 0.85–0.96), Statement (0.88; CI 0.85–0.90), Standard (0.87; CI 0.84–0.89), K-type (0.81; CI 0.68–0.90) and Case-based (0.81; CI 0.78–0.83). The small sample size of the K-type and True/False items prevented any conclusions. Therefore, only Case-based, Standard and
Statement items, which had an overall difficulty index of 0.84 (CI 0.83–0.86), were analysed further. Items formatted as Case-based were statistically more difficult than Standard (P = 0.0007) or Statement items (P = 0.001). The rank order of increasing discrimination by format was True/False (0.18; CI 0.10–0.26), Standard (0.22; CI 0.21–0.24), Statement (0.24; CI 0.22–0.26), Case-based (0.25; CI 0.23–0.26) and K-type (0.26; CI 0.22–0.29). As mentioned above, only Case-based, Standard and Statement items, which had an overall discrimination index of 0.24 (CI: 0.23–0.25), were analysed further. Case-based items were more discriminatory than Standard (P = 0.015) but not Statement (P = 0.7) items. We analysed 294 therapeutics items, 162 dosing items and 60 pathophysiology items. The overall difficulty index was 0.85 (CI: 0.83–0.86).