Factors associated with psychological and physiological stress reactions to blood donation: a systematic review of the literature.

Abstract

Blood donation is generally seen as a safe, voluntary and socially useful activity, based on the altruism of donors1. A number of positive effects of blood donation are described in scientific literature, such as feelings of satisfaction, feelings of being more alert and feeling better in general2. However, the majority of the literature concerning blood donation describes adverse events, such as fatigue, vasovagal symptoms, fainting and bruises2–5. In addition to the discomfort experienced by the donor, these might also impede blood donation in the future. Studies report that up to 10 to 20% of donors experience such adverse events6,7. For a blood supply organisation, it is crucial to maintain the donor pool in order to be able to deliver an optimal supply of blood. This can be achieved by recruiting new donors and retaining existing ones. Either way, negative donor experiences should be kept to a minimum. In blood donor research, several studies have investigated the occurrence of adverse events, retention, or the interaction between adverse events and retention. For instance, Bravo et al. investigated factors associated with fainting and donating blood and showed that vasovagal reactions are more common during or after phlebotomy than during registration8. Newman et al. showed that donors who experienced an adverse event were less likely to return to the blood centre9. In line with this, Veldhuizen et al. showed a strong association between reporting a vasovagal reaction and stopping donating, especially among men6. Adverse events may upset the donors, causing increased anxiety. However, despite some indications that anxiety is increased before and during donating blood10, it remains largely unclear what factors are associated with such a stress reaction. Stress reactions are quite common phenomena11,12. Various factors, known as stressors or stress stimuli, can induce a stress reaction. Although any situation and any object may elicit a stress reaction, the resulting stress experience may differ between individuals and circumstances12. After being confronted with a stressor, a psychological stress reaction occurs, which can consist of higher levels of anxiety, irritation, fear, worry, tension or anger13. At the same time, physiological stress reactions take place, such as increases in the levels of cortisol and (nor-)adrenaline14, a decrease in heart rate variability15, and negative changes in blood coagulation parameters16. As mentioned earlier, blood donation does not always elicit positive feelings, but can be accompanied by anxiety-eliciting factors as well8–17. These factors (stressors) may induce a stress reaction. The relation between blood donation on the one hand, and anxiety and stress reactions on the other remains largely unclear. Although stress reactions (e.g. anxiety) do seem to be present, the factors capable of inducing or enhancing these reactions (i.e. stressors) are largely unidentified. The aim of this study was, therefore, to perform a systematic review of the literature in order to evaluate existing knowledge on the following research question: what factors are associated with psychological and physiological stress reactions in blood donors in a blood donation setting? We hypothesised that both physiological (e.g. increased levels of adrenaline or cortisol) and psychological (e.g. increased levels of anxiety or fear) stress reactions take place in a blood donation setting. We also hypothesised that a greater stress reaction would be associated with factors such as donation-related adverse events, e.g. bruises or fainting, as opposed to not experiencing such an event. Knowing and identifying potential stressors could help to optimise the donation experience for the donor.