Transplant Trial Watch

Anticipated regret and organ donor registration: A randomized controlled trial.

O'Carroll RE, Shepherd L, et al.

Health Psychology 2016; 35(11): 1169-1177.


Aims
To investigate whether simply asking people to rate the extent to which they anticipate feeling regret for not registering as an organ donor after death increases subsequent verified organ donor registration.

Interventions
The study involved 4 interventions with participants randomized to 1 of 4 arms, each receiving different questionnaires. The no-questionnaire control (NQC) arm received a survey measuring demographics and whether or not they were registered organ donors. The questionnaire control (QC) arm completed the NQC questions plus questions regarding affective attitudes and intention to register as an organ donor. The theory of planned behaviour (TPB) questionnaire arm received the QC questionnaire, plus additional items measuring TPB variables. The anticipated regret (AR) arm received the TPB questionn

Participants
Adult, Scottish, members of the general public, not registered on the NHSBT before the application pack was sent, were eligible for the study.

Outcomes
The primary outcome measures were number of nondonor participants who subsequently registered 6 months later, as verified by the United Kingdom national transplant register.

Follow-up
6 months

CET Conclusions
This RCT tested whether the emotional factor anticipated regret can be used for interventions aimed at increasing organ donor registration. A randomly selected sample of 14,509 members of the general public were randomised to one of four intervention arms using simple randomisation. The four intervention arms each received a different questionnaire and participants were blind to the experimental arm. The sample size calculation showed that 3,630 participants were needed, which was based on the results of a pilot study, taking into account the proportion of the population already registered as an organ donor and an expected low response rate to questionnaires. The intention to treat analysis of 9,208 participants, showed that 5.4% of participants registered as an organ donor after receiving the questionnaire. However participants in the anticipated regret intervention arm were less likely to register compared with the no-questionnaire control arm. The authors suggest that future research should take into account the possible effect of items in a questionnaire on the effectiveness of a proposed intervention.

Jadad score
4

Data analysis
Modified intention-to-treat analysis

Allocation concealment
No

Trial registration
ISRCTN - 92204897

Funding source
Non-industry funded