[Informed consent as viewed by patients participating in cardiology drug trial]

In clinical tests, the Informed Consent is critical to preserve the ethics, but due to its high complexity level, it cannot be fully understood. This study assesses the Informed Consent as viewed by patients.

We addressed the issue of what do patients understand about the studies based on the IC.

We invited participants of outpatient clinical drug trials phase II, III and IV to answer a questionnaire with 29 questions, such as: why have you accepted to participate? Did you read the Informed Consent before signing it? By signing it, were you sure you have fully understood it? Eighty individuals (20 women and 60 men) showed up, from 106 patients. The variables of each question were considered as often as they appeared. The comparison of the averages among the groups was made by t tests of Student or Wilcoxon; and for associations, Chi-square or Likelihood Ratio, or Fisher's exact test.

Ages averaged 58.7 +/- 9.3 years. Concerning their reasons to taking part in the survey, 66.2% pointed out their own benefit; 42.5%, for science's sake; 25.0% claimed they were doing so at their doctor's request; 50% did not understand the Informed Consent properly; and 32.9% did not read it, but signed it. Among those who were administered placebo after randomization (n = 47), 66.7% did not understand the meaning of the informed consent. A strong correlation between failure to understand the meaning of placebo with literacy level (p = 0,02) was verified, which is an evidence that the smaller is the literacy level, the smaller is the understanding level.

The Informed Consent is poorly understood by patients and for some of them, trusting a doctor affected their decision in taking part in the clinical trial with drugs. Their literacy level also influenced their understanding of the term 'placebo'.