Estimating the risk of blood donation fainting for self versus others: the moderating effect of fear.

Abstract

People overestimate the likelihood that blood donors will experience faint and prefaint reactions, particularly if they are themselves fearful of having blood drawn. This study investigated the influence of making a risk assessment for oneself versus others, and examined whether providing information about the low base rates of reactions affected donation attitude, anxiety, and intention. An anonymous online survey was completed by 3702 individuals (53.9% female; mean age, 36.9 years; standard deviation, 12.1 years; range, 18-84) that included questions about fear of having blood drawn and estimation of the risk of donation-related faint and prefaint symptoms for themselves and others. A random one-half of the respondents received accurate information about the proportion of whole blood donors who experience such reactions before all participants completed questions concerning their donation attitude, anxiety, and intention. Estimates of both faint and prefaint reactions revealed a pattern of lower perceived risk for self versus others among individuals with low fear, and higher perceived risk for self versus others among those with high fear. Provision of accurate information about risk of reactions was associated with more positive donation attitudes (F[1, 3692] = 8.182, p = 0.004) and intentions (F[1, 3692] = 10.137, p = 0.001) but did not significantly affect anxiety. Donation-related fear is associated with inflated expectancies of adverse events, especially regarding oneself. Such fear may be particularly important to address, as it has both a direct and indirect negative effect on donor retention.