Informed consent for early-phase clinical trials: therapeutic misestimation, unrealistic optimism and appreciation.

Unrealistic therapeutic beliefs are very common-the majority of patient-subjects (up to 94%) enrol in phase 1 trials seeking and expecting significant medical benefit, even though the likelihood of such benefit has historically proven very low. The high prevalence of therapeutic misestimation and unrealistic optimism in particular has stimulated debate about whether unrealistic therapeutic beliefs in early-phase clinical trials preclude adequate informed consent. We seek here to help resolve this controversy by showing that a crucial determination of when such therapeutic beliefs are ethically problematic turns on whether they are causally linked and instrumental to the motivation to participate in the trial. Thus, in practice, it is ethically incumbent on researchers to determine which understanding and beliefs lead to the participant's primary motivation for enrolling, not to simply assess understanding, beliefs and motivations independently. We further contend that assessing patient-subjects' appreciation as a component of informed consent-it is already an established component of decision-making capacity assessments-can help elucidate the link between understanding-beliefs and motivation; appreciation refers to an individual's understanding of the personal significance of both the medical facts and the experience of trial participation. Therefore, we recommend that: (1) in addition to the usual question, 'Why do you want to participate in this trial?', all potential participants should be asked the question: 'What are you giving up by participating in this trial?' and (2) researchers should consider the settings in which it may be possible and practical to obtain 'two-point consent'. © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.