Psychometric properties of an aptitude test administered to Sri Lankan first-year medical students

Introduction: Selection for basic medical training is highly contextual. The use of cognitive aptitude tests, which commonly supplement measures of prior academic achievement in the selection process of medical schools internationally, is rarely reported from resource-constrained settings in South Asia. We report on the psychometric properties of an aptitude test designed based on the UCAT format, administered to first-year medical undergraduates to determine its utility. Methods: The aptitude test was administered online to first-year medical students shortly after their admission to two medical faculties in Sri Lanka (n=328). The reliability of the test was determined using Cronbach's alpha. Overall and subtest scores were computed, and the scores of different demographic groups were compared using the t-test. Factor analysis of the subtests was performed. Results: The internal consistency of the test was 0.63. The difficulty and discrimination indices were within the acceptable range. The mean score of the aptitude test (AT) was 70.9/100 (SD 8.88). The mean score for females was higher than for males (p=0.04). No statistically significant differences in AT scores were observed between different ethnicities or religions. The entry academic scores demonstrated a weak correlation with the overall AT score (Pearson's correlation coefficient r=0.27), verbal reasoning (r=0.24), the human body (r=0.19), quantitative reasoning (r=0.18), and situational judgement (r=0.128). Factor analysis indicated items that need revision. Conclusion: The results indicate the potential value of aptitude tests in Sri Lanka and in similar jurisdictions where selection criteria have yet to expand beyond prior academic performance. A way forward in introducing such tests has been outlined.