Effect of prior clinical experience on students' knowledge and performance in surgery.

Approaches to designing an optimal surgical curriculum and studies of validity and reliability of students' evaluations have neglected the potential effect of prior clinical experience, although this admittedly increases greatly from those entering surgery as the first clinical clerkship to those taking surgery after completion of all other clinical rotations. The present study assesses students' knowledge on entering the surgery clerkship, reevaluates knowledge, assesses performance on completion of the surgery clerkship, and determines the effect of prior clinical experience on both knowledge and performance. Four hundred fifty consecutive students were evaluated during 2 academic years with a 100-question multiple-choice pretest, posttest, two oral examinations, and three subjective evaluations by surgical faculty members and housestaff. Reliability of the multiple choice examinations averaged 0.70 as determined by the KR-21 coefficient. Both mean pretest and posttest scores decreased with increasing clinical experience, mainly due to loss of preclinical knowledge. Nevertheless, scores on subjective evaluations increased. Regression analysis demonstrated positive intercorrelation among the subjective evaluations but no correlation to the objective forms of evaluation. It is suggested that multiple-choice examinations lack the ability to assess clinical competence and decision-making skills, qualities that are better evaluated by faculty members. The efficiency of teaching methods and the fairness of final grades may benefit from recognition of the effects of prior clinical rotations.