A study involving over 8,700 patients, which was published in the New England Journal of Medicine, has found that the gender of blood donors does not impact the survival rate of recipients who undergo red blood cell transfusions.
According to Dr. Dean Fergusson, a senior scientist at The Ottawa Hospital, Director of the hospital's Clinical Epidemiology Program, and professor at the University of Ottawa, previous observational studies had suggested a potential association between female donor blood and increased risk of death among recipients compared to male donor blood. However, the recent clinical trial involving over 8,700 patients contradicts these findings, concluding that the sex of the blood donor does not have any significant effect on the survival of recipients who undergo red blood cell transfusions.
The potential influence of the sex of a blood donor on the survival of recipients has been a topic of inquiry in the field of transfusion medicine since 2015, when it was identified as a research priority by the American National Heart, Lung, and Blood Institute. Some studies had indicated that sex-related differences, such as hormone levels in male and female blood, could impact the survival of recipients. However, the findings from observational studies have been inconsistent and have not provided a definitive answer to this question.
Dr. Michaël Chassé, who served as a co-lead author of the study and is an intensivist at Centre hospitalier de l'Université de Montréal and an associate professor at Université de Montréal, highlighted that answering this question definitively required a large randomized clinical trial, which can be prohibitively expensive. However, the study was able to provide valuable insights by incorporating the trial into real-world clinical practice and utilizing practical methods, resulting in a significant cost reduction compared to traditional clinical trials. This approach allowed for a more cost-effective way to obtain meaningful results and shed light on the impact of blood donor sex on recipient survival.
The research team estimated that the traditional trial methods for this study would have incurred a cost of $9 million. However, their innovative approach resulted in a significantly reduced cost of $300,000. The approach involved enrolling all eligible adult patients at The Ottawa Hospital who might require a blood transfusion, randomly assigning them to receive either male or female blood, and then collecting data from existing hospital databases and provincial registries. As both male and female blood were considered equivalent treatments, patients were not required to provide written consent to participate in the trial, but were given the option to opt out after the first transfusion. This pragmatic approach allowed the team to successfully enroll 8,719 participants in a double-blind, randomized trial within a timeframe of just over two years.
The study had certain limitations, including the exclusion of patients without an Ontario Health Insurance Plan (OHIP) number, as well as those who required immediate blood transfusions due to massive bleeding or had complex antibody profiles that posed challenges in blood unit matching. These exclusions may have impacted the generalizability of the study's findings to these specific patient populations. It is important to consider these limitations when interpreting the results and applying them to clinical practice, as they may not fully represent the broader population of patients receiving blood transfusions in all clinical scenarios. Further research may be needed to investigate the impact of blood donor sex on recipient survival in these excluded patient populations.
Study participants were randomly assigned to receive either male or female donor blood at all visits to The Ottawa Hospital during the study period. Eighty per cent of patients received their first transfusion while they were an inpatient, and 42 per cent of those received it during surgery.
Patient characteristics, laboratory and clinical data, and blood bank data were obtained from The Ottawa Hospital Data Warehouse. Blood donor data from Canadian Blood Services was linked with hospital data and health administrative data at ICES.
The study found no statistically significant differences in overall survival between recipients of male donor blood and recipients of female donor blood. (PB/Newswise)