Motives for joining an unrelated HSC donor registry: description, categorization, and association with donor availability.

A challenge for registries of unrelated hematopoietic stem cell (HSC) donors is to recruit and retain sufficient donors for patients needing transplants. Many registered HSC donors opt-out when called as a potential match for a patient. Anecdotal evidence suggests that motives for joining a registry may be linked to the donation decision. The primary goals of this investigation were to describe the range of motives for joining a registry and to examine donor availability by motive type. A diverse sample of 357 potential HSC donors from the Anthony Nolan registry in the UK was asked about their motives for joining and their decision to continue or opt-out after matching a patient was recorded. Motives for joining (N = 557) were first coded and categorized into 17 specific motive types and then arranged along a spectrum from internal to external. Internal values-based motives were most prevalent and availability was highest among potential donors expressing these motives (92%) and lowest among those expressing external motives (pressure, incentives; 0%). Although further research is needed to confirm these findings, they suggest that registries should assess donors' motives for joining at recruitment in order to conduct follow-up to ensure commitment among those potential members expressing external motives.