Internship is a critical period during which fifth-year medical students develop clinical competence because they have clinical activities with patients and they select the hospital to do it with an average of 4 years previous since the highest to the lowest. During this year they pass 2 months in each discipline area of Internship and at the end of this period they have a written exam with clinical cases and multiple choice questions. UNAM Faculty of Medicine currently uses OSCE exams for formative and end-of-career summative purposes. Several studies show low correlation between OSCE and written exams. (van der Vleuten, 1990, Prislin 1998, Wilkinson, 2004)

The correlation of post-internship OSCE scores with average grades and pre-internship OSCE show students' consistency. The correlation between written test and OSCE scores in the end-of-career summative exam provide supportive evidence for validity. There was no unique variable with high predictive value for the final OSCE (postest). 

Generalized use of formative OSCE before the Internship could allow for provision of feedback to students, faculty and curriculum developers.

The objective of the study was to correlate OSCE scores before Internship (5^th year of medical school), with average grades of previous 4 years, written exams during Internship, written summative exam, and the end-of-career OSCE summative exam. We applied an 18 stations OSCE to 278 medical students before the start of internship to assess clinical competence(pre-test), and an equivalent OSCE at the end of the year (postest). We used check lists at the stations and global ratings for communication skills. The clinical cases in the stations were focused on general medicine (history taking, physical exam, diagnostic and management, X-ray interpretation, laboratory studies interpretation and Analysis of published literature). The clinical cases of stations were classified into the six disciplines: Surgery, Gyn & Obstetrics, Family Medicine, Internal Medicine, Pediatrics and Emergencies. We got the average of 4 years previous and the written exams scores of the same 278 students to do the correlation studies. 

Pre-test OSCE global mean score was 55.4 ± 6.6 and the post-test score was 63.2 ± 5.7 (p<0.001). Cronbach’s alpha was 0.62 for the pre-test and 0.64 for the post-test. Pearson's correlation coefficients were:

1) Moderate correlations   among OSCE postest and written summative exam (r=0.44), with OSCE pretest (r=0.44) with average grades of the previous 4 years (r=0.39), all were significant (p<.0001).

2) Low correlation between OSCE (postest) with written exams during Internship ( r= 0.21) and with each discipline.