A decrease from 8 to 6 weeks in obstetrics and gynecology clerkship: effect on medical students' cognitive knowledge.

We undertook this study to determine whether a decrease in the amount of time a third-year medical student spent in an obstetrics and gynecology clerkship would cause a decrease in the knowledge of the subject. We compared National Board of Medical Examiners (NBME) obstetrics and gynecology subject examination scores of 168 students at the University of Texas Medical Branch at Galveston completing an 8-week obstetrics and gynecology rotation or the 1989-1990 academic year to scores of 187 University of Texas Medical Branch students competing a 6-week rotation during 1990-1991. No significant change in the total mean NBME subject examination score in obstetrics and gynecology was noted after the decrease in rotation length. Passing scores were those greater than 445 points. The failure rate for those students who completed the 8-week rotation was consistent throughout the 1989-1990 academic year. In contrast, those students who rotated through obstetrics and gynecology during the 6-week clerkship in the first half of the academic year had a failure rate that was statistically higher than those taking the clerkship in the last half of the year. The length of the obstetrics and gynecology clerkship was shortened to 6 weeks without significantly affecting students' overall performance on the NBME obstetrics and gynecology subject examination. However, a greater percentage of students who completed the rotation during the first half of the year scored low on the NBME obstetrics and gynecology subject examination than did those taking the rotation and thus the NBME subject examination in the second half of the year.