Results from the blood donor competence, autonomy, and relatedness enhancement (blood donor CARE) randomized trial

Abstract

Background: This study aimed to promote competence, autonomy, and relatedness among first-time whole blood donors to enhance intrinsic motivation and increase retention.

Study design and methods: Using a full factorial design, first-time donors (N = 2002) were randomly assigned to a no-treatment control condition or to one of seven intervention conditions designed to promote donation competence, autonomy, relatedness, a combination of two (e.g., competence and autonomy), or all three constructs. Participants completed donor motivation measures before the intervention and 6 weeks later, and subsequent donation attempts were assessed for 1 year.

Results: There was no significant group difference in the frequency of donation attempts or in the number of days to return. Significant effects of group were observed for 10 of the 12 motivation measures, although follow-up analyses revealed significant differences from the control group were restricted to interventions that included an autonomy component. Path analyses confirmed direct associations between interventions involving autonomy and donor motivation, and indirect mediation of donation attempts via stronger donation intentions and lower donation anxiety.

Conclusion: Among young, first-time, whole blood donors, brief interventions that include support for donor autonomy were associated with direct effects on donor motivation and indirect, but small, effects on subsequent donation behavior.

Keywords: blood donation; first-time donors; motivation; retention.

Figure 1.

Participant flow diagram. Interventions are coded as C (competence), A (autonomy), or R (relatedness).

Figure 2.

Path analysis of the relationships among donation intervention, assessment measures, and subsequent donation attempts. Only significant pathways are illustrated, with the exception of paths from baseline assessment measures to the equivalent post-intervention measure, which were all significant at p < 0.001 but are not illustrated for clarity.

Figure 3.

Predicted probability of a subsequent donation attempt for the four interventions (i.e., Autonomy; Competence + Autonomy; Autonomy + Relatedness; Competence + Autonomy + Relatedness) that differed significantly from controls on baseline-adjusted post-intervention intention. The intervention curves are all higher than control, but they cannot be distinguished due to their overlap.