The Design and Validation of a Self-Assessment Questionnaire of Critical Appraisal of Medical Literature Skills in Medical Students.

Introduction: Critical appraisal of medical literature is a challenging step of the evidence-based medicine practice. Many assessment questionnaires have been published in the literature, but they have mainly focused on all the evidence-based medicine practice process. The authors aimed to develop and validate a questionnaire assessing the critical appraisal skills of medical students from the same Faculty.

Methods: The questionnaire was developed by item generation through a review of the literature and an expert committee. The questionnaire was validated in terms of content validity and construct validity. Fitness of data for analysis was checked through Kaiser-Meyer-Olkin (KMO) and Bartlett's sphericity. Construct validity was carried out using a principal axis exploratory factor analysis (EFA) with 'varimax' rotation to study the internal structure of the questionnaire and to extract the test major factors. The questionnaire was administrated to a cohort of under and postgraduate medical students (n=84) to evaluate the test reliability and select the best items. The reliability of the questionnaire was assessed by Cronbach's alpha coefficient to evaluate the internal consistency. The correlations between the self-confidence and satisfaction dimension score, the critical thinking dimension score, the learning style dimension score, the Fresno-adapted test scores and the total score were assessed using the Spearman's correlation test.

Results: The questionnaire consisted of 31 items. A factorial analysis grouped the items into 3 dimensions that consisted of the self-confidence and satisfaction dimension, the critical thinking dimension and the learning style dimension. Cronbach's alpha accounted for 0.95, CI95% [0.9-1] for the entire questionnaire. The factor analysis explained 79.51% of the variance. The external validity assessment based on a Spearman's correlation study highlighted a weak correlation between the total scores and the critical thinking dimension and the self-perception and satisfaction dimension.

Conclusion: In spite of the limitations of this study, mainly the small number of the students recruited, the questionnaire seems to measure with adequate reliability the competences of under and postgraduate medical students.