Modifying a standard industry clinical trial consent form improves patient information retention as part of the informed consent process

Abstract

Objective: Informed consent is a required part of clinical research. Industry consent forms may be complex and difficult to understand. A comparison was performed between a standard, industry consent form (IF) and a modified, shortened version of the same form (MF) to determine which allows the patient to retain more information in the immediate postconsent period.

Methods: This was a prospective, randomized study performed in an urban, county teaching emergency department (ED). A convenience sample (based on the availability of one of two research assistants being present in the ED) of 100 patients with a history of asthma seen in the ED were enrolled. After reading the consent form, 50 MF and 50 IF patients were given a postconsent test to determine how much information was retained. Mean differences in test scores between the IF and MF were determined.

Results: The population had a mean age (+/-SD) of 39.4 +/- 12.1 years (range 18-80); 52% were female. The overall score for the study population was 9.6 (+/-2.0), range 2-12 (maximum 12). The MF score was 10.6 (+/-1.4) vs the IF score of 8.6 (+/-2.1); mean difference = 2.0 (95% CI = 1.3 to 2.7, p < 0.0001). The MF group had significantly more correct answers than the IF group with the following questions (MF%, IF%; mean difference in proportions with 95% CIs): purpose (96, 70; 26, 95% CI = 12 to 40); randomization (78, 44; 34, 95% CI = 16 to 52); study duration (94, 70; 24, 95% CI = 10 to 38); risks (92, 74; 18, 95% CI = 4 to 32); benefits (94, 78; 16, 95% CI = 3 to 29); alternative treatments (88, 70; 18, 95% CI = 2 to 34); confidentiality (98, 88; 10, 95% CI = 0.2 to 20); and voluntary participation (74, 54; 20, 95% CI = 2 to 38). Adverse event compensation had the poorest correct rate (54, 38; 13, 95% CI = -6 to 32). Subsequently, after taking the postconsent test, 98% wrote that they read the entire MF, while only 68% wrote that they read the entire IF (mean difference in proportions 30%, 95% CI = 17% to 43%).

Conclusions: Compared with an industry consent form, a shortened version, focusing on Food and Drug Administration and Department of Health and Human Services informed consent guidelines, allowed patients to retain more information in the immediate postconsent period.