Impact of risk-dependent interventions on low haemoglobin deferral rates in whole blood donors

Background: Blood donors with a relatively low haemoglobin (Hb) level at their previous donation attempt have an increased risk of Hb deferral at the subsequent donation attempt. The aim of this study was to investigate whether the interventions prolongation of donation interval and/or a dietary advice decrease the Hb deferral rate. Methods: 11 897 whole blood donors with Hb levels from below to 0·2 mmol/l above the cut-off level for donation received either no intervention, a prolongation of the donation interval to six or twelve months, a dietary advice, or both. Deferral rates for low Hb levels at the subsequent donation attempt were compared in the different intervention groups. Additionally, the effects of the interventions on Hb deferral risk and donor return for a subsequent donation attempt were analysed using generalized estimating equations. Results: The Hb deferral rate was substantially lower in the group that received a prolongation of the donation interval to six months than in the Control Group (12·9% vs. 6·3% in men and 20·4% vs. 13·4% in women). However, the additional benefit of twelve over 6-month interval prolongation was small, and no benefit of a dietary advice showed up. On the other hand, receiving a dietary advice increased the likelihood of donor return for a subsequent donation attempt. Conclusion: Implementation of a protocol for the prolongation of donation intervals to six months for donors with Hb levels from below to slightly above the cut-off level for donation may reduce the deferral rate for low Hb levels while keeping donor lapse at a minimum.