Importance Blood donors are at increased risk for iron deficiency. Current hemoglobin (Hb) monitoring policies are inadequate and new iron management strategies are warranted.Objective To determine the effects of ferritin-guided donation intervals for whole blood donors on Hb and ferritin levels, Hb deferral, iron deficiency (ferritin Design Between November 2017 and November 2019 a ferritin-guided donation interval policy was gradually implemented nationwide and evaluated through a stepped-wedge cluster-randomized controlled trial.Setting All blood collection centers in the Netherlands.Participants 412,888 whole blood donors were included.Interventions Ferritin was measured in all new donors and at every 5th whole blood donation. Subsequent donation intervals were extended to six months if ferritin is 15 ≤ 30 ng/mL and to twelve months if ferritin is Main outcomes and Measures The primary outcomes are ferritin and Hb levels, iron deficiency, Hb deferral, and donor return. Secondary outcomes are self-reported iron deficiency-related symptoms.Results We measured 36,099 donors, median age 43 years and 52% female, making 37,621 donations during the study period. Ferritin-guided donation intervals increased log-transformed ferritin levels at all time points in the trial, up to 0.56 log-transformed ng/mL as compared to baseline (95% CI 0.49 – 0.63, p Conclusion and Relevance Ferritin-guided donation intervals significantly increased overall Hb and ferritin levels, thereby decreasing the prevalence of iron deficiency and Hb deferrals in whole blood donors. Ferritin-guided donation intervals seem beneficial for Hb levels and iron maintenance, but additional efforts are required to retain donors and to remedy self-reported iron deficiency-related symptoms.Trial Registration This trial has been registered in the Dutch trial registry (NTR6738) on September 29th,, 2017 (https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6738).
Meulenbeld et al. (Wed,) studied this question.