Stigmatizing deferrals disproportionally reduce donor return rates: Evidence from Brazil.

Background and objectives: Prior research has shown that temporary deferrals negatively influence donor return rates, but it remains unknown the extent to which these effects vary across reasons for deferral. We investigate whether deferrals differ in their degree of perceived stigmatization and, if so, how being deferred for stigmatizing (vs. non-stigmatizing) reasons affects subsequent donation behaviour.

Materials and methods: We examined whether reasons for deferral vary on their perceived level of stigmatization through an online survey (n = 400). Furthermore, we used a dataset encompassing 25 years of donation records from the state-run blood collection agency (BCA) from Rio de Janeiro, Brazil, to investigate how stigmatizing (vs. non-stigmatizing) reasons for deferral affected return rates of 82,648 donors over a 60-month follow-up period.

Results: Being deferred for sex- and drug-related reasons was perceived as much more stigmatizing than other reasons for deferral (odds ratio = 3.14, 95% confidence interval [CI]: 2.33-4.25). Controlling for multiple observables, prospective donors were less likely to return to the BCA when deferred for stigmatizing (vs. non-stigmatizing) reasons (adjusted hazard ratio = 0.87, 95% CI: 0.83-0.93).

Conclusion: Donors perceive deferrals motivated by sex- and drug-related reasons as particularly stigmatizing, which is negatively associated with donor return rates. BCAs may want to pay special attention when communicating stigmatizing reasons for deferral to prospective donors.