Norm perception and communication for vasovagal symptoms in blood donation

Blood is a valuable resource, but most people do not donate. One deterrent to blood donation is the anticipation of vasovagal symptoms (e.g., dizziness, nausea, and fainting), despite the fact that such symptoms typically affect a small proportion of donors. The current research examined norm perceptions regarding vasovagal symptom experiences and used a message-framing paradigm to communicate accurate norm information and increase future donation intentions.

Three studies were conducted using young adult samples. In Study 1, donors and nondonors estimated the percentage of people who experience vasovagal symptoms. In Studies 2 and 3, nondonors and donors (respectively) were provided with accurate, positively framed, or negatively framed norm messages and indicated their intentions to donate.

In Study 1 we found that participants vastly overestimated how normative it was to experience vasovagal symptoms and this overestimation was stronger among nondonors. In Studies 2 and 3, we showed that positively framed normative messages ("90% of donors do not experience vasovagal symptoms") were generally more influential than negatively framed messages ("10% of donors do experience vasovagal symptoms"), except among past donors who had unfavorable donation experiences.

These findings suggest that targeting and correcting norm perception may be a critical step toward improving blood donation rates.