Effect of Donor Sex on Recipient Mortality in Transfusion.

BACKGROUND: Conflicting observational evidence exists regarding the association between the sex of red-cell donors and mortality among transfusion recipients. Evidence to inform transfusion practice and policy is limited. METHODS: In this multicenter, double-blind trial, we randomly assigned patients undergoing red-cell transfusion to receive units of red cells from either male donors or female donors. Patients maintained their trial-group assignment throughout the trial period, including during subsequent inpatient and outpatient encounters. Randomization was conducted in a 60:40 ratio (male donor group to female donor group) to match the historical allocation of red-cell units from the blood supplier. The primary outcome was survival, with the male donor group as the reference group. RESULTS: A total of 8719 patients underwent randomization before undergoing transfusion; 5190 patients were assigned to the male donor group, and 3529 to the female donor group. At baseline, the mean (±SD) age of the enrolled patients was 66.8±16.4 years. The setting of the first transfusion was as an inpatient in 6969 patients (79.9%), of whom 2942 (42.2%) had been admitted under a surgical service. The baseline hemoglobin level before transfusion was 79.5±19.7 g per liter, and patients received a mean of 5.4±10.5 units of red cells in the female donor group and 5.1±8.9 units in the male donor group (difference, 0.3 units; 95% confidence interval [CI], -0.1 to 0.7). Over the duration of the trial, 1141 patients in the female donor group and 1712 patients in the male donor group died. In the primary analysis of overall survival, the adjusted hazard ratio for death was 0.98 (95% CI, 0.91 to 1.06). CONCLUSIONS: This trial showed no significant difference in survival between a transfusion strategy involving red-cell units from female donors and a strategy involving red-cell units from male donors. (Funded by the Canadian Institutes of Health Research; iTADS ClinicalTrials.gov number, NCT03344887.).

Pragmatic, double-blind, randomised trial evaluating the impact of red blood cell donor sex on recipient mortality in an academic hospital population: the innovative Trial Assessing Donor Sex (iTADS) protocol.

INTRODUCTION: With over 1 million units of blood transfused each year in Canada, their use has a significant clinical and economic impact on our health system. Adequate screening of blood donors is important to ensure the safety and clinical benefit of blood products. Some adverse transfusion reactions have been shown to be related to donor factors (eg, lung injury), whereas other adverse outcomes have been theoretically related to donor factors (mortality and infection). Our clinical trial will test whether male donor blood leads to a greater benefit for transfusion recipients compared with female donor blood. METHODS AND ANALYSIS: We have designed a pragmatic, double-blind, randomised trial that will allocate transfusion recipients to receive either male-only or female-only donor transfusions. We will enrol 8850 adult patients requiring at least one transfusion at four sites over an approximate 2-year period. Randomisation and allocation will occur in the blood bank prior to release of the units of blood for transfusion. Our primary outcome is mortality. An intent-to-treat analysis will be applied using all randomised and transfused patients. The principal analysis will be a survival analysis comparing the time from randomisation to death between patients allocated to male donor red blood cells (RBCs) and female donor RBCs. ETHICS AND DISSEMINATION: Approval has been obtained from research ethics boards of all involved institutions, as well as from privacy offices of Canadian Blood Services, Institute for Clinical Evaluative Science and The Ottawa Hospital Data Warehouse. Our findings will be published in peer-reviewed journals and presented at relevant stakeholder conferences and meetings. TRIAL REGISTRATION NUMBER: NCT03344887; Pre-results.