Clinical Trials in Rheumatology: Assessing Trends of Informed Consent

The considerable progress that has been achieved in medical research over time has not led to improvements in the process of informed consent forms in industry-sponsored randomized controlled trials in rheumatology, according to data published in Seminars in Arthritis and Rheumatism. The disparity between the readability of informed consent forms with patients’ health literacy and their understanding of the forms persists, even after decades of attempts by regulatory agencies and published suggestions.

Researchers evaluated the readability of informed consent forms at an outpatient rheumatology clinic in Mexico between 1999 and 2016. The INFLESZ scale, an adaptation to Spanish of the Flesch Reading Ease Formula, was used to assess the readability of informed consent forms. Patients’ health literacy was evaluated using the Short Assessment of Health Literacy for Spanish Adults and the Short Test of Functional Health Literacy in Adults. In addition, patient opinions were evaluated using a self-reported in-office questionnaire with an independent sample of patients who had signed an informed consent form in the previous 6 months.

Overall, 39 informed consent forms about 22 drugs from 13 different pharmaceutical companies were examined. Global mean readability was 57±3 (95% CI, 56-58). All informed consent forms were classified as being either “somewhat difficult to read” or “average.” From 1999 to 2016, readability remained at these levels without any significant changes. The mean length of the informed consent forms written between 1999 and 2005 was 13±5 pages, with a significant increase reported thereafter (mean length, 22±8 pages; P =.004).

Among 95 patients who participated in the health literacy evaluation, between 18% and 44% exhibited limited health literacy, depending on the instrument that was used. Moreover, among 90 patients who participated in the perceptions questionnaire, 84% reported that they understood the informed consent form well. Nevertheless, between 2% and 57% of the participants misunderstood basic concepts, including the name of the study drug and placebo. The placebo concept was defined correctly by only 43% of patients, and 32% regarded placebo as being a useful drug for their disease.

The investigators concluded that the disparity reported between readability of informed consent forms and patients’ health literacy might be attributable to differences in the “cognitive framework” of patients when compared with the sponsor, researchers, and physicians who are involved in the development of informed consent forms.

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Reference

de la Mora-Molina H, Barajas-Ochoa A, Sandoval-Garcia L, et al. Trends of informed consent forms for industry-sponsored clinical trials in rheumatology over a 17-year period: readability, and assessment of patients’ health literacy and perceptions [published online March 16, 2018].  Semin Arthritis Rheum. doi: 10.1016/j.semarthrit.2018.03.008