Therapeutic misconception, misestimation, and optimism in participants enrolled in phase 1 trials

Ethical concerns about phase 1 trials persist. Important conceptual advances have been made in understanding concepts used to describe misunderstanding. However, a systematic, empirical evaluation of the frequency of misunderstanding incorporating recent developments is lacking.

The authors queried 95 participants in phase 1 trials to provide a more sophisticated estimate of the proportion who had therapeutic misconception (TM), defined as misunderstanding the research purpose or how research differs from individualized care, and therapeutic misestimation (TMis), defined as incorrectly estimating the chance of a research trial benefit as >20% or underestimating risk as 0%.

Sixty-five of 95 respondents (68.4%) had TM, which was associated in a multivariate analysis with lower education and family income (P = .008 and P = .001, respectively), but TM was not associated with the vulnerability of having hardly any treatment options. Eighty-nine of 95 respondents (94%) had TMis, although only 18% reported this was a factual estimate. Although the risks of investigational agents and those exacerbated by research, such as uncertain outcomes, were mentioned (39% and 41% of respondents, respectively), risks novel to research, such as research biopsies, were rarely mentioned (3% of respondents). Although most of these respondents believed that their chance of benefit was greater and that their risk was lower than the population chance (optimists) (54.6%), a substantial minority of respondents (37.6%) were pessimists.

TM continues to be prevalent. Estimates of personal benefit were not usually meant to report facts, it remains unknown whether respondents in the current study had TMis. Although they are not more vulnerable, phase 1 participants need improved understanding of key TM concepts, with attention to risks that are not present in standard of care.