Providing extra information increases blood donor return after deferral while offering an alternative good deed does not: Results from a field randomized controlled trial

Donating blood (components) is considered a “good deed,” especially in voluntary, nonremunerated contexts where blood is donated for unknown recipients. For donor and recipient safety, blood banks apply deferral criteria. Deferred donors are less likely to return for future donations. Based on theory (e.g., on emotion, habit, and identity) and practice, several methods have been suggested to encourage return after deferral, yet few of these methods have been tested in rigorous study designs, or in the field. In this study, we therefore investigated whether offering an alternative “good deed” or providing additional information about deferral would increase donor return. Results of a randomized controlled field trial at 10 Dutch blood donation centers showed that offering alternative good deeds after deferral did not significantly increase donor return, while providing additional information did increase whole blood donor return. This suggests that additional information contributes to the continuation of pro-social behavior.