The association between blood donor sex and age and transfusion recipient mortality: an exploratory analysis

Abstract

BACKGROUND There is recent support for long‐term adverse effects of donor‐recipient sex‐mismatched red blood cell (RBC) transfusion, but short‐term impact is unknown. A retrospective exploratory analysis was performed using data from a research database. METHODS Adults admitted to hospitals in one Canadian center who received RBCs (2008–2014 [3 sites]; 2012–2014 [1 site]) were eligible. Patient data were extracted from a research database and donor data from the blood supplier. Cox regression models were used, with control of risk and confounding variables as covariates or using stratification. Exposure was defined by mutually exclusive categories. The outcome was in‐hospital mortality. RESULTS A total of 25,219 adults received 97,886 RBCs. Diagnoses included cardiovascular (28.8%), neoplastic (15.6%), traumatic (15.4%), or gastrointestinal (10.5%); 56.3% of transfused RBCs were male donors, and median donor age was 45 years (interquartile range, 30–54). Female patients exposed to male RBCs experienced a higher risk of in‐hospital death (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.02–1.69; p = 0.038) compared to exclusive female RBC exposure. Exposure to RBCs from donors aged 45 years or younger was associated with a higher in‐hospital death (HR, 1.21; 95% CI, 1.02–1.44; p = 0.026) compared to exclusive RBC exposure to donors older than 45 years. Donor‐recipient sex‐mismatched RBC exposure (vs. exclusively sex‐matched) and RBC exposure from donors aged 45 years or younger (vs. exclusively RBCs from donors >45) were associated with increased mortality: sex‐mismatched (HR, 1.23; (95% CI, 1.04–1.45; p = 0.017); donors aged 45 years or younger (HR, 1.21; (95% CI, 1.02–1.43; p = 0.031). CONCLUSION Donor‐recipient sex‐matched RBC transfusions and transfusions from older donors may benefit patients.

Growing evidence supports healthy older people continuing to donate blood into later life

“…While it appears that older donors can donate without undue health or safety risks to themselves, it is important to consider the quality and safety of the products donated by these donors and any implications for the recipients. Researchers have reported that exposure to RBCs from donors aged 45 years or younger are associated with increased patient mortality compared to blood from older donors; although others have interpreted the available evidence as indicating that the age of donors of RBC units is unlikely to impact the survival of patients receiving a transfusion . Research into the impact of donor age on RBC storage is under way, with suggestions that a predisposition to oxidative hemolysis is modulated by donor age .…”

Blood donor–recipient sex mismatch: outcomes impacted?

“…From this perspective, it is interesting to note that Heddle et al . found increased signal from sex mismatch in the direction of male donor red cells to female recipients .…”

“…1 to ≤12 years) was included in 6 studies . An increased short‐term mortality signal was noted in two studies (Middelburg et al . did not demonstrate an increase in mortality until 90 days ).…”

Association of donor age, body mass index, hemoglobin, and smoking status with in‐hospital mortality and length of stay among red blood cell–transfused recipients

“…We conducted secondary analyses of donor age and hemoglobin levels, stratifying by donor sex, given known differences in hemoglobin levels by sex and the results of previous publications. 2,3 Because the number of transfusions was one of the stratifying variables, comparisons were done only between patients who received the same number of transfusions. The data were set up for analysis using the Andersen-Gill counting process format using the publicly available Stratify macro.…”

“…mortality, while other studies finding no such associations. [1][2][3][4][5][6] Differences in the studied sample size, proportions of missing data, and statistical methods may explain these variable results. 7 However, there may be other blood donor characteristics, not previously accounted for, that have relevance to mortality of transfusion recipients.…”