Assessing readability and comprehension of informed consent materials for medical device research: A survey of informed consents from FDA's Center for Devices and Radiological Health

Legally effective informed consent has been a long-standing requirement for FDA-regulated clinical studies. However, informed consent forms (ICFs) are often thought to be too long, too complex, and too difficult for participants to understand. In this article, investigators from the FDAs Center for Devices and Radiological Health (CDRH) surveyed 399 ICFs from approved investigational device exemption (IDE) applications for fiscal years 2015 and 2016 to evaluate the readability of ICFs. The investigators collected data from the ICFs, using variables related to structure, readability, and comprehension. The investigators found that the mean grade-reading levels of the ICFs ranged from 10th grade to college level (Table 2), higher than the recommended 6th to 8th grade level, when measured by major readability evaluation tools (the SMOG readability grade level formula, the Flesch-Kincaid Index Grade Level Readability Formula, the Flesch Reading Ease test, and the Dale-Chall readability formula). Overall, the ICFs and informed consent (IC) processes, as described in the IDE application, lacked components that enhanced participants' comprehension, such as short sentences (e.g., no more than 8 to 10 to words) and the use of pictures, tables, and diagrams. CDRH investigators believe that information about ICFs' readability, comprehension, and structure will help support current and future efforts to improve the IC process. The intent of the article is to demonstrate that improvements are needed in the IC process and to encourage clinical trial stakeholders to consider implementing those approaches that optimize patient comprehension in the development of their IC processes.