The Evidential and Ethical Weight of Opt-Out Consent: An Empirical Bioethical Examination.

Opt-out consent for posthumous organ donation has been criticized for its lower evidential weight: a person's not opting out of donation is poorer evidence of their preferences than their opting in to it, because their not opting out could be due to unawareness, inertia, or lack of preference. Do people also perceive opt-out consent to have lower evidential weight, and how does this affect their downstream ethical judgments about the validity of consent and the appropriateness of families overriding it? Could the evidential weight of opt-out consent be augmented, and if so, how? In this paper, I use two survey experiments to address these questions. First, I find that when a potential donor has merely not opted out of donation (rather than opted in to it), participants are less likely to judge that this person has given valid, informed consent; are more likely to judge that hospitals should uphold a familial challenge to their consent; and are more likely to judge that this person prefers the family to override their decision. Secondly, I evaluate three augmentation measures that aim to increase this evidential weight; I find substantial public alignment with the theoretical claim that the consent process should involve a "selective occasion". I then draw some ethical implications about the deficiencies of opt-out consent and how we might improve it.