Best-fit model of exploratory and confirmatory factor analysis of the 2010 Medical Council of Canada Qualifying Examination Part I clinical decision-making cases

PURPOSE This study aims to assess the fit of a number of exploratory and confirmatory factor analysis models to the 2010 Medical Council of Canada Qualifying Examination Part I (MCCQE1) clinical decision-making (CDM) cases. The outcomes of this study have important implications for a range of domains, including scoring and test development. METHODS The examinees included all first-time Canadian medical graduates and international medical graduates who took the MCCQE1 in spring or fall 2010. The fit of one- to five-factor exploratory models was assessed for the item response matrix of the 2010 CDM cases. Five confirmatory factor analytic models were also examined with the same CDM response matrix. The structural equation modeling software program Mplus was used for all analyses. RESULTS Out of the five exploratory factor analytic models that were evaluated, a three-factor model provided the best fit. Factor 1 loaded on three medicine cases, two obstetrics and gynecology cases, and two orthopedic surgery cases. Factor 2 corresponded to pediatrics, and the third factor loaded on psychiatry cases. Among the five confirmatory factor analysis models examined in this study, three- and four-factor lifespan period models and the five-factor discipline models provided the best fit. CONCLUSION The results suggest that knowledge of broad disciplinary domains best account for performance on CDM cases. In test development, particular effort should be placed on developing CDM cases according to broad discipline and patient age domains; CDM testlets should be assembled largely using the criteria of discipline and age.