A randomized control trial of re-designed and shorter research informed consent forms to improve comprehension

Background/Aims: Informed consent forms are an essential component of ethical clinical research. However, they are failing. They are long, legalistic, and written at an 11th-grade reading level. Consequently, many participants have poor comprehension of the research they are considering. Our objective is to assess participant comprehension and satisfaction across three informed consent forms of different lengths and formats including one based on the Food and Drug Administration’s (FDA) 2024 draft summary template. Methods: In total, 334 healthy participants from AmeriSpeak’s online survey panel were recruited via email and AmeriSpeak’s member portal, oversampling less educated individuals and those from racial and ethnic minority groups. Participants were randomized to three informed consent forms—long, medium, and short—and were asked to imagine hypothetically being a patient considering joining a study. They were given a brief introduction on the purpose of informed consent forms and of this project’s goal to evaluate comprehension, satisfaction, and willingness to join the described hypothetical study but were not told the hypothesis or that there were three different informed consent forms. The long informed consent form (21 pages) was used in an actual international Bristol Myers Squibb study concerning a stroke prevention regimen. The long informed consent form contained longer paragraphs and lists and was written just below an 11th-grade level. The long informed consent form was modified to create the medium (14 pages) and short informed consent forms (3 pages), which both used simpler words, shorter sentences, less passive voice, tables, and other patient-friendly edits to achieve below sixth-grade reading levels. The short informed consent form was adapted from the Food and Drug Administration’s 2024 draft summary template. Results: The medium informed consent form (mean score of 79.3%) scored significantly higher on comprehension than the long informed consent form (65.7% mean score, p < 0.001) or the short informed consent form (69.3% mean score, p = 0.006). Compared to the long informed consent form, fewer medium informed consent form participants found their informed consent form “too long” or “too detailed.” Compared to the long and medium informed consent forms, more short informed consent form participants reported wanting more information on study procedures. Conclusion: The medium-length informed consent form, written at a sixth-grade reading level, with shorter words and sentences, tables, and enhanced formatting, produced significantly better comprehension than longer or shorter informed consent forms. The short informed consent form produced the same level of comprehension as a long informed consent form used in approved clinical trials. Researchers, pharmaceutical companies, and institutional review boards should adopt these informed consent form modifications to increase participant comprehension and satisfaction.