Vasovagal syncope and blood donor return: examination of the role of experience and affective expectancies.
Blood donors come back when their past trips feel easy and their body feels steady, not when they simply expect it will.
01Research in Context
What this study did
Atladóttir et al. (2010) asked blood donors how they felt after giving blood. They wanted to know who would come back to donate again.
The team used a survey. People rated their vasovagal symptoms, past donation trips, and future plans.
What they found
Two things predicted return: how strong the dizzy or faint feelings were, and how many times the person had donated before.
Expectations alone did not decide. Real body cues and real past trips mattered more.
How this fits with other research
Goldman et al. (1979) showed that adults can learn to notice blood-pressure changes when they get quick feedback. O et al. extend this idea: people already use body cues to guide future choices, even without training.
Bhaumik et al. (2009) treated public-speaking fear by changing expectancies with VR. O et al. find that expectancies are only part of the story; lived bodily experience carries extra weight. The papers do not clash—they simply target different links in the chain: one changes thoughts, the other shows thoughts plus body history drive action.
Schmausser et al. (2024) boosted vagal tone with daily ear-clip stimulation and saw calmer moods. O et al. show that natural vagal events (syncope) push behavior in the opposite direction—away from repeat donation. Together they hint that vagal signals are powerful levers, whether you raise or lower them.
Why it matters
If you run blood drives, do not rely only on pep talks. Ask donors how faint or dizzy they feel right after the bag comes off. First-timers who report strong symptoms are at risk for never returning. Offer them water, a longer rest, and a follow-up text to schedule the next visit. These small supports target the exact variables O et al. found matter most.
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02At a glance
03Original abstract
Vasovagal sensations (e.g., dizziness, nausea, and fainting) are one of the main reasons people find blood donation unpleasant. A better understanding of predictors of vasovagal sensations during blood donation could inform interventions designed to increase donor return rates. The present investigation examined the extent to which experience with blood donation and vasovagal sensations during blood donation uniquely predict the likelihood of donor return, even when controlling for affective expectancies. Participants presenting at community blood drives indicated how many times they have given blood and provided ratings of expected anxiety, pain, disgust, as well as fear of fainting before giving blood. After donating, participants completed a measure of vasovagal sensations experienced during blood donation. They also rated the pleasantness of the experience and willingness to donate blood in the future. The findings showed that experience with blood donation and vasovagal sensations during blood donation uniquely predicted willingness to donate blood in the future even when controlling for age and negative affective expectancies about giving blood. This finding suggests that vasovagal sensations and experience with blood donation have unique (and perhaps additive) effects on willingness to donate blood in the future, suggesting that behavior modification interventions that directly target these variables could potentially increase donor retention.
Behavior modification, 2010 · doi:10.1177/0145445510362576