Using the Health Action Process Approach to predict blood donation intentions and return behavior following a vasovagal reaction for whole blood and plasma donors.

<bold>Background: </bold>To inform the development of interventions to retain donors following a vasovagal reaction (VVR), the aim of this study is to use the Health Action Process Approach (HAPA) to identify predictors of intentions to re-donate and actual return behavior among whole blood (WB) and plasma donors who experienced a VVR.<bold>Study Design and Methods: </bold>A total of 1136 WB donors (Mage  = 32.4 ± 12.5 years; 73.4% female) and 1141 plasma donors (Mage  = 36.5 ± 14.4 years; 73.3% female) completed an online survey after experiencing a VVR. Two hierarchical regression analyses were conducted for each donation type. In the first analysis, donation intentions were regressed onto the motivational HAPA constructs and social support. In the second analysis, donor return within 6 months was regressed onto social support, intentions, and the volitional HAPA constructs.<bold>Results: </bold>The motivational and social support variables accounted for 47.2% of the variance in intentions to return in WB donors and 15.7% in plasma donors. For both groups, task self-efficacy, positive and negative outcome expectancies, and social support were significant predictors of intentions to return. Intentions and action planning were significant predictors of donor return in both groups, and recovery self-efficacy was significant for plasma only.<bold>Conclusion: </bold>The HAPA model can provide guidance to blood collection agencies to design phase-specific and individually-focused interventions to retain WB and plasma donors following a VVR. [ABSTRACT FROM AUTHOR]