Objective: To objectively measure the effect of a pass-fail grading system on stress, mood, group cohesion, and test anxiety in medical students.
Participants and methods: Beginning with the class of 2006, the Mayo Medical School, Rochester, Minn, changed the grading system for first-year courses from a 5-interval grading system to a pass-fail grading system. Students in the previous class of 2005, who were graded using a 5-interval system during their first year of medical school, were compared with students in the class of 2006. Using a prospective study design, the 2 groups were compared at the end of both the first year and the second year of medical school on the Perceived Stress Scale, Profile of Mood States, Perceived Cohesion Scale, Test Anxiety Inventory, and (after year 2) the United States Medical Licensing Examination Step 1. Data collection occurred in 2002 and 2003 with the class of 2005 and in 2003 and 2004 with the class of 2006.
Results: Students graded with the pass-fail system had less perceived stress (median, 15.0 vs 21.0; P-.01) and greater group cohesion (median, 34.5 vs 30.0; P=.02) at the end of their second year of coursework than their 5-interval graded peers. The pass-fail group had better mood (median, 46.5) than the graded group (median, 64.0), but this difference was not statistically significant (P=.07). No significant differences were found between the 2 groups in test-taking anxiety or in United States Medical Licensing Examination Step 1 board scores.
Conclusion: Pass-fail grading may reduce stress and increase group cohesion in medical students compared with traditional 5-interval grading.