Background: Informed consent forms (ICFs) for oncology clinical trials have grown increasingly longer and more complex. We evaluated objective understanding of critical components of informed consent among patients enrolling in contemporary trials of conventional or novel biologic/targeted therapies.
Methods: We evaluated ICFs for cancer clinical trials for length and readability, and patients registered on those studies were asked to complete a validated 14-question survey assessing their understanding of key characteristics of the trial. Mean scores were compared in groups defined by trial and patient characteristics.
Results: Fifty patients, of whom half participated in trials of immunotherapy or biologic/targeted agents and half in trials of conventional therapy, completed the survey. On average, ICFs for industry-originated trials (N = 9 trials) were significantly longer (P < .0001) and had lower Flesch ease-of-reading scores (P = .003) than investigator-initiated trials (N = 11). At least 80% of patients incorrectly responded to three key questions which addressed the experimental nature of their trial therapy, its purported efficacy and potential risks relative to alternative treatments. The mean objective understanding score was 76.9±8.8, but it was statistically significantly lower for patients who had not completed high school (P = .011). The scores did not differ significantly by type of cancer therapy (P = .12) or trial sponsor (P = .38).
Conclusions: Many participants enrolled on cancer trials had poor understanding of essential elements of their trial. In order to ensure true informed consent, innovative approaches, such as expanded in-person counseling adapted to the patient's education level or cultural characteristics should be evaluated across socio-demographic groups.
Trial registration: Clinicaltrials.gov NCT01772511.