Patient comprehension and reaction to participating in a double-blind randomized clinical trial (ISIS-4) in acute myocardial infarction

Background: Although randomized clinical trials are currently the standard for the evaluation of new therapeutic strategies, little attention has been paid to the viewpoint of the patients recruited to these trials. Objective: To examine the perspective of the Israeli patient cohort who participated in the Fourth International Study of Infarct Survival, a randomized trial in acute myocardial infarction. Methods: A patient questionnaire was mailed to 360 Israeli patients who participated in the Fourth International Study of Infarct Survival and was returned by 150 of them. Main outcome measures included patient perception of consent procedures, comprehension of the study, subjective reaction to participating in the trial, and interest in present and future trials. Results: Forty (31%) of 129 patients perceived that they had full comprehension of the trial, while 64 (50%) claimed partial understanding and 25 (19%), no understanding at all. Comprehension was related to a recol- lected explanation of 5 minutes or more (P<.001) and to an opportunity for discussion at the time of consent (P<.001). Most patients recollected the oral explanation; fewer, the written material. Patient consent was given by 64 (43%) of 150 patients in the hope of better treatment. In 36 cases (25%), the patients felt they received better treatment because of participation in the trial. Conclusions: Despite proper attention to accepted ethical and legal standards, perceived patient comprehension in this trial in acute myocardial infarction was incomplete or lacking in a considerable number of subjects. Much progress must be made toward the goal of true informed consent in clinical trials.