Item analysis of multiple choice questions based undergraduate assessment in community medicine

Background: Multiple Choice Question (MCQ) based assessments are ubiquitous now, yet the emphasis on training of teachers in preparing good MCQs is inadequate. There are very few studies reporting use of item analysis of MCQs in medical education from India. Hence, we present this simple psychometric analysis of MCQs.

Methods: An item analysis was performed on an internal assessment test paper with 50 MCQs faced by 158 final year undergraduate students (6th and 7th semester) in Community Medicine during the year 2011. The following indicators of item analysis were derived; 1. Response rate for each item, 2. Facility Value (FV), 3. Discrimination index (DI), 4. Distractor efficiency and 5. Cronbach‟s alpha(α). Microsoft Office Excel was used for analysis.

Results & Discussion: The mean score (±2 SD) of the students was 27.2/50 (15.8 – 38.6), and 54% of the items had a response rate of more than 95%. Out of 50 items on the test, 19 and 22 items were in the acceptable range of FV and DI respectively. Only 12 items were in acceptable range of both. 36% distractors achieved a below optimal response rate (<5%). Cronbach‟s alpha was 0.66.

Conclusion: The analysis helped us detect the technical flaws in the single paper scrutinized. Reporting of matrix of the items falling in different ranges of FV and DI was found to be more informative, as it would help improve the quality of the items in our bank.