Is informed consent to clinical trials an "upside selective" process in acute coronary syndromes?

Patient understanding of clinical trial details was assessed on 2 occasions (10 +/- 4 and 24 +/- 3 hours after randomization) in 20 patients enrolled for randomized investigation of pharmacotherapy for unstable angina pectoris or non-Q-wave myocardial infarction in the Platelet IIb/IIIa Antagonist for the Reduction of Acute Coronary Syndrome Events in a Global Organized Network (PARAGON B) and Organization to Assess Strategies in Ischemic Syndromes (OASIS-2) trials.

Initial total score for understanding of 52.0% (+/-15.7%) of maximal values improved to 67.7% (+/-18.3%) at repeat interview (P <.001). The mean initial score for knowledge of potential benefit was 85.0% (+/-33.3%) with no significant improvement at repeat interview. Scores for knowledge of risk improved from 35.0% (+/-36.6%) to 68.2% (+/-41.2%) at repeat interview (P <.005). Significant determinants of poor initial score were female sex, limited education, and presence of pain during the consent process; young age was the only determinant of improvement on repeat assessment.

Thus initial understanding of the research protocols for patients with unstable angina pectoris or non-Q-wave acute myocardial infarction was imperfect, with far greater impairment of knowledge of risk than of benefit.