Prospective evaluation of patient comprehension of informed consent

Physicians and society may overestimate the level of patient comprehension during the process of obtaining informed consent for medical and surgical treatment. The purpose of this study was to prospectively measure the immediate level of patient comprehension at the time that surgical consent is obtained and the effect of time on this level of understanding. In addition, we studied the effect of sex, education level, and age on comprehension.

One hundred patients scheduled for elective orthopaedic surgery were enrolled voluntarily into this study. Following discussion of risks and benefits with the surgeon and a reading and explanation of the entire consent form, each patient immediately completed a questionnaire to test recall of the information that had just been reviewed. The same questionnaire was administered to each patient at the first postoperative visit and, if applicable, again at the second postoperative visit. Age, sex, education level, and questionnaire scores were recorded.

Ninety-eight patients completed the questionnaire preoperatively and scored an average of 70.7% correct answers. Seventy-five patients completed the first postoperative questionnaire, scoring an average of 59.5%. Thirty-nine patients completed the second postoperative questionnaire, scoring an average of 60.8%. The decline between the preoperative and the first postoperative score was significant. The mean score did not differ significantly according to sex at any time point. College-educated patients scored higher than patients without a college education did on both the preoperative and postoperative questionnaires, with the difference in the preoperative score being significant. Patients who were less than fifty years old scored higher than older patients did, with the difference in the postoperative score being significant.

Patient comprehension and recall immediately following a thorough discussion of the consent form was unexpectedly low. This poor recall deteriorated further between the preoperative visit and the first postoperative visit (a period of no more than two weeks). Greater age and lower education level were associated with poorer comprehension. Sex did not affect any of the scores.