Donation frequency of blood donors participating in a prospective cohort study of iron status

The determinants of frequent donation and factors that lead to high return rates among volunteer blood donors are increasingly important as the eligible donor population continues to be reduced. Deferrals for medications, travel, lifestyle, and emergent diseases and the increasing age of the donor population decrease the pool of available donors. To address concerns about the adequacy of the blood supply, blood centers need to not only recruit new donors but to understand what motivates donors to give again to improve donor retention and increase donation frequency. Previous studies have suggested that the total number of first-time donors is decreasing1 and that only 8% of those new donors continue donating.2 Other reports suggest that younger and minority donors were less likely to donate again within 12 months,3 shorter intervals between a first and second donation increased the likelihood of subsequent donations,4 and first-year donation frequency is a strong predictor of long-term donor return.2 Variables such as age, ethnicity, blood type, and education have also been shown to influence donor return behavior.4 The Retrovirus Epidemiology Donor Study-II (REDS-II) Donor Iron Status Evaluation (RISE) study was a prospective cohort study of hemoglobin (Hb) and iron metabolism in first-time and frequent blood donors. By the midpoint of the 15-month study it became clear that RISE subjects in both cohorts were presenting to donate blood more frequently than predicted. This analysis sought to determine if the reason(s) for higher-than-expected donor return rates involved the donor’s participation in a nonremunerated study.