[Diagnostic assessment of knowledge and competencies in medical students at the end of the second year of medical school: the challenge of building an airplane while it's flying].

Introduction: In Latin America there is almost no published information about knowledge retention and formative assessment of competencies in medical students, during medical school training and curricular changes.

Objective: To assess knowledge level and clinical competencies in medical students at the end of the second year in a new curriculum.

Methods: Observational, cross-sectional study in UNAM Faculty of Medicine students. A diagnostic evaluation was performed in the first class of the "Plan of Studies 2010" curriculum, as part of an integral program evaluation strategy. The assessment had two components: theoretical and practical.

Results: 456 (87%) of the 524 students that successfully completed the second year of Plan 2010 were assessed. The written test had 211 items, a mean score of 60 ± 14.5, mean difficulty index of 0.60, reliability with Cronbach's alpha of 0.85. The OSCE mean global score was 58 ± 9, Cronbach's alpha of 0.36, and G-coefficient of 0.48, and results were provided for each station. Results by area of knowledge, course, and station were reported.

Conclusions: The results in general are acceptable, compared with previous written evaluations at the end of the second year, suggesting that the new program is achieving its educational goals. Competencies were formally assessed for the first time in our Institution, establishing a starting point for follow-up. The study provided useful information to the institution, teachers and students.