The effect of testing time on students' performance for the subject examination for internal medicine.

The authors tested the hypothesis that increasing the allotted testing time from two to four hours for the National Board of Medical Examiners medicine subject examination would increase the score on this examination when given as part of the clerkship evaluation. One-hundred six students who completed their medicine clerkships between September 1991 and August 1992 (group 1) were compared with 96 students who completed their clerkships between September 1992 and August 1993 (group 2). The mean medicine subject examination score for group 1 was 462 +/- 86, vs 518 +/- 108 for group 2 (p = 0.0003). Regression analysis using the medicine subject examination score as the dependent variable and all baseline characteristics, group assignment, and time of year the test was taken as independent variables demonstrated significant interactions only for United States Medical Licensing Examination (USMLE) Step 1 score (R2 = 0.48, beta weight = 0.68, p = 0.0000) and group assignment (R2 = 0.05, beta weight = 0.18, p = 0.002). The authors conclude that increased testing time for the medicine subject examination from two to four hours is associated with a significant increase in scores; however, scores on the preclinical USMLE Step 1 showed a stronger association.