biostudies-literatureShepherd LBritish Academy825-835https://www.ebi.ac.uk/biostudies/studies/S-EPMC11264565biostudies-literatureUnknown29(8)In contrast to opt-in systems, relatively little is known about what influences whether or not people register a decision about organ donation in opt-out systems. We address this gap in the literature. Participants (<i>N</i> = 756) living in a country with opt-out consent (Wales, UK) provided information on demographics and blood donor status. Participants indicated whether they had opted-in or opted-out (i.e. active decision), or not registered a decision under the assumption of deemed consent. Subsequently, their negative emotional beliefs (or affective attitudes) towards organ donation were measured. Opting-in was associated with being younger, having donated blood and holding superstitious beliefs about donation (jinx). Disgust (ick factor) deterred opting-in, and bodily integrity concJournal of health psychologyAssessing the influence of affective attitudes, demography and blood donor status on organ donor registration active decisions in opt-out systems.PMC11264565SRG1819/191190Shepherd LO'Carroll REFerguson EfalseAssessing the influence of affective attitudes, demography and blood donor status on organ donor registration active decisions in opt-out systems.In contrast to opt-in systems, relatively little is known about what influences whether or not people register a decision about organ donation in opt-out systems. We address this gap in the literature. Participants (<i>N</i> = 756) living in a country with opt-out consent (Wales, UK) provided information on demographics and blood donor status. Participants indicated whether they had opted-in or opted-out (i.e. active decision), or not registered a decision under the assumption of deemed consent. Subsequently, their negative emotional beliefs (or affective attitudes) towards organ donation were measured. Opting-in was associated with being younger, having donated blood and holding superstitious beliefs about donation (jinx). Disgust (ick factor) deterred opting-in, and bodily integrity conc2024-01-01T00:00:00Z2024 Jul2025-05-18T13:27:27.004Z2025-05-18T13:27:27.004ZS-EPMC112645653796892110.1177/13591053231208531