This research project was funded by a grant from the Chief Scientist Office of £162,650, awarded to Professor Ronan O’Carroll (University of Stirling), Professor Eamonn Ferguson (University of Nottingham), and Professor Peter Hayes (University of Edinburgh). This project started on the 3rd October 2011 and ended in April 2013.

Project summary

There is a lack of donor organs to meet the demand for organ transplantations worldwide. The NHS Blood and Transplant (NHSBT) Annual Report (2009-2010) found that 90% of the UK general public approve of organ donation. Despite this, only 30% of people in the UK (37% in Scotland) have registered as posthumous organ donors. This research assessed whether asking people whether they would later regret not registering as an organ donor increases registration. Previous work by Professor O’Carroll and his team found that simply asking people whether they would later regret not registering as an organ donor increased their intentions to register (O’Carroll et al., 2011a) and self-reported registration (O’Carroll et al., 2011b). In this project we aimed to extend this research further by testing whether asking people whether they would later regret not registering increases verified registrations on the UK NHS Blood and Transplant (NHSBT) Organ Donor Register.

A representative sample of the adult Scottish general public was sampled via post and invited to complete a short questionnaire. Six months later, we asked NHSB-T to search the Organ Donor Register to see how many of the people involved in this research had become registered organ donors. We predicted that asking people whether they would later regret not registering as an organ donor should increase registration. If successful, this intervention has the potential to increase the number of UK NHSBT registered organ donors and could be used in future organ donation campaigns.

The project protocol is available here:


This project is based on three pilot studies that were run by Professor O’Carroll and his team. These pilot studies can be found in the following papers:

O’Carroll, R.E., Dryden, J., Hamilton-Barclay, T., & Ferguson, E. (2011a).Increasing organ donor registration using anticipated regret: A pilot study. Health Psychology, 30, 661-664.

O’Carroll, R.E., Foster, C., McGeechan, G., Sandford, K., & Ferguson, E. (2011b). The 'ick' factor: Anticipated regret and willingness to become an organ donor. Health Psychology, 30, 236-245.


Lee Shepherd was appointed as the designated post-doctoral Research Fellow for the INORDAR project. He will be responsible for the day-to-day management and running of the trial. He is an experienced researcher who has previously investigated the effect of anticipated emotions on people’s behaviour.

The project completed in April 2013.

Key results

14,509 members of the general public (both registered and non-registered donors) were randomly allocated to 1 of 4 treatment groups, each receiving different questionnaires. The no-questionnaire control (NQC) group received a survey to collect information on age, gender and whether or not they were registered organ donors, but did not complete any questions about their views of organ donation. The questionnaire control (QC) group completed the NQC questions plus questions regarding affective attitudes (including disgust (the 'ICK' factor), jinx, and medical mistrust), and intention to register as an organ donor. The theory of planned behaviour (TPB) questionnaire group received the QC questionnaire, plus additional items measuring TPB variables (i.e. attitudes towards organ donation, social norms (i.e. views of others), and perceived control). The anticipated regret (AR) group received the TPB questionnaire, plus two additional items measuring anticipated regret e.g. 'If I did not register as an organ donor in the next few months, I would later wish I had'.

The main outcome measure was the number of non-donor participants who subsequently registered as an organ donor, collected six months later, as verified by the UK national transplant register.

People who were already registered as organ donors and those who did not receive the questionnaires (e.g. address details incorrect) were not included in the analysis.

Intention-to-treat (ITT) analysis (N = 9,139) revealed the NQC arm were more likely to register as an organ donor (6.4%) compared to the AR (4.5%) arm. Thus, receiving the AR questionnaire led to an apparent lower rate of organ donor registration. However, when we examined individuals’ scores on anticipated regret (by a median split into low and high regret groups); registration rates were significantly higher in the high versus low anticipated regret group, with 59/118 participants (50.0%) registered as an organ donor in the high regret group, and 11/73 participants (15.1%) in the low regret group. These results demonstrated a strong association between higher self-reported anticipated regret and increased organ donor registrations.

A potential reason for the higher registration rate in the no questionnaire groups could be because the intervention groups were exposed to negative items regarding organ donation (e.g. the ‘ICK’ factor, anticipated regret) and this exposure increased across treatment groups. We therefore conducted an analysis coding for increased exposure to negative item content (0 = NCQ, 1 = TPB + QC, and 2 = AR) to see what, if any effect, this had on registration. We also considered whether participants had completed the active questionnaire items (e.g. the AR questions) and therefore had definitely been exposed to the intervention. We found that both exposure to active ingredients and randomization to intervention groups with more negative items resulted in lower registration rates.


This study found that a simple AR intervention did not increase organ donor registration. Instead, participants in the AR arm were less likely to register as an organ donor than those in the no questionnaire control arm. This may have been because people in this arm were also induced to think about reasons to not donate (e.g. the 'ick' factor), whereas control participants may not have had such reasons readily available to them. Researchers should consider the potential influence of each item in a questionnaire to ensure that the inclusion of affective attitude items does not reduce the effectiveness of their proposed intervention.

It should be stressed that the findings do not indicate that AR interventions are likely to be unsuccessful, as higher self-reported regret was associated with higher rates of organ donor registration. However, this large-scale questionnaire-based intervention was not effective overall.

The main findings are expected to be published shortly and we will update this page as soon as they are available.


If you have any queries about the project, please do not hesitate to contact Professor Ronan O’Carroll on