Identifying beliefs about posthumous organ donation among young Australian adults using an augmented theory of planned behaviour framework

BACKGROUND: The Australian Organ Donor Register (AODR) was established as a way to facilitate the dissemination of posthumous organ donation wishes to next of kin. Unfortunately, young Australian adults are substantially less likely to have recorded their donation wishes on the AODR than older cohorts. AIM: The aim of this thesis was to examine the decision-making processes used by young Australian adults aged 18-24 years when considering whether to record their organ donation wishes on the AODR. METHODS: In Study 1, a meta-synthesis of the qualitative findings from 24 studies was conducted to identify the beliefs that members of the general community could potentially have towards organ donation. In Study 2, a dimensional salience approach was used to examine the salience and prevalence of the beliefs identified in Study 1 among a sample of 352 Australians aged 18 to 24 years. The processes that underpin the decision to become a registered organ donor were then examined further using an augmented multi-component theory of planned behaviour (TPB) framework. RESULTS: Eight themes, each encapsulating a set of beliefs about organ donation, emerged through the qualitative meta-synthesis. These themes centred on issues associated with: religion; death; benevolence; personal relevance; the body; the family; the medical profession; and transplant recipients. The salience of the beliefs associated with these themes was then examined in Study 2. Using a dimensional salience approach, five beliefs were found to be differentially salient for individuals who were either willing or undecided about becoming a registered organ donor. These beliefs were that organ donation: (i) saves or improves the lives of others; (ii) ensures that organs do not go to waste; (iii) helps the community; (iv) risks having the body treated with disrespect; and (v) is upsetting to family members. The dimensional salience approach was also found to resolve the ‘expectancy-value muddle’, a statistical issue that has invalidated previous efforts to incorporate belief-based expectancy-value models within the TPB. Using this dimensional salience approach, a modified expectancy-value framework was found to explain 21% of the variance in both attitude and intention towards becoming a registered organ donor. Finally, the predictive utility of an augmented multi-component TPB framework was evaluated. The descriptive norm and self-efficacy components of the multi-component TPB could not be discriminated from injunctive norm and intention, respectively. As a result, descriptive norm and self-efficacy were not examined further. The remaining multi-components, namely affective attitude, instrumental attitude, injunctive norm, and controllability, were found to account for 58% of the variance in registration intentions. Inclusion of anticipated regret and self-identity to this abridged multi-component TPB model increased the proportion of explained variance to 67%. CONCLUSIONS: Many young Australian adults appear to be undecided about whether to record their organ donation wishes on the AODR. Approaches for encouraging the registration of donation wishes among this population were considered, and potential areas for future research discussed