How well informed is the informed consent for cancer clinical trials?

Abstract

Aims: The purpose of this study was to analyze the content of informed consent forms for clinical trials in medical oncology to assess readability, determine their completeness, and identify any shortcomings.Methods: Informed consent forms for Phase I-III studies that were conducted at two tertiary care cancer centers over a 3-year period were reviewed. Information pertaining to length of the informed consent form, research regimen/methods, treatment agent, potential risks, and benefits was extracted. The reading level was assessed by Flesch-Kincaid and Gunning-Fog index readability tests.Results: All of the 112 informed consent forms clearly stated the voluntary nature of participation. Nearly one half of the forms (51.8%) were of Phase I studies. The median length of informed consent form was 20 pages (range: 8-28). A detailed estimation of the frequency or intensity of risks (range: 3-8 pages) was provided. The average reading level of the informed consent forms was high (Flesch-Kincaid Grade Level of 9.8), which corresponds roughly to 10th-grade reading level. Less than 15% of all consent forms were written at the recommended eighth-grade reading level. A substantial number of forms did not report a potential risk to pregnant/lactating women (16.9%), mechanism of action of the investigational agent (34.8%), study schema (77.6%), a possibility of receiving sub-therapeutic dose (37%), or death (12.5%). Nearly one half of the forms (49.1%) stated clearly that individual participants may not benefit.Conclusion: Overall, these informed consent forms provided a detailed description of the trials in accordance to international guidelines. However, there remains room for improvement, particularly in areas of readability and document length.