Effectiveness of Ferritin-guided Donation Intervals in Blood Donors: Results of the Stepped-wedge Cluster Randomised FIND’EM Trial

Abstract

AbstractBackgroundWhole blood donors are at increased risk for iron deficiency and anaemia. The current standard of haemoglobin (Hb) monitoring is insufficient to ensure the maintenance of proper iron reserves and donor health. We determine the effects of ferritin-guided donation intervals for blood donors and the blood supply.MethodsA ferritin-guided donation interval policy was implemented and evaluated through a stepped-wedge cluster-randomised controlled trial in all blood collection centres in the Netherlands. Ferritin was measured in new donors and at every 5th donation. Subsequent donation intervals were extended to six months if ferritin was 15 - 30 ng/mL and to twelve months if ferritin was <15 ng/mL. Primary outcomes are ferritin and Hb levels, iron deficiency, Hb deferral, and donor return. Secondary outcomes are self-reported iron deficiency-related symptoms. Operational statistics assessed the impact on the blood supply.FindingsAmong 412,888 whole blood donors, 36,099 were measured. Ferritin-guided intervals increased ferritin levels by 0.24 log10 ng/mL (95% CI 0.22 – 0.27, p <0.001) and Hb by 0.37 g/dL (95% CI 0.31 –0.43, p <0.001). Donors were less likely to be iron deficient (OR 0.15, 95% CI 0.10 – 0.21, p <0.001) or deferred based on Hb (OR 0.23, 95% CI 0.11 – 0.41, p <0.001). However, donors returned less frequently (OR 0.60, 95% CI 0.51 – 0.67, p <0.001), necessitating more invitations and reducing the average donation frequency. No improvement in self-reported symptoms was observed.InterpretationFerritin-guided donation intervals significantly improved Hb and ferritin levels, reducing iron deficiency and Hb deferrals. While beneficial for iron and Hb maintenance, efforts are needed to recruit and retain donors and remedy self-reported symptoms.Funding and registrationThis project received support from the ’Product and Process Development Cellular Products Grant’ (PPOC18-15) granted to K. van den Hurk by the Research Programming Committee of Sanquin. The trial was registered in the Dutch trial registry (NTR6738) on September 29th, 2017 (https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6738).