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Effects of Donor-recipient Sex-matched Blood Transfusion on Patient Outcomes

Effects of Donor-recipient Sex-matched Versus Sex-mismatched Red Blood Cell Transfusion on Outcomes in Critically Ill Adult Patients

Status
Recruiting
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06840756
Acronym
SexMATTERS RCT
Enrollment
11082
Registered
2025-02-21
Start date
2025-09-11
Completion date
2029-03-31
Last updated
2026-03-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiovascular, Critically Ill Intensive Care Unit Patients, Health Services, Hematology, Red Blood Cell Transfusions, Sex Differences

Keywords

transfusions, red blood cell transfusions, sex-matched, sex-mismatched, intensive care unit, ICU, cardiovascular, circulatory, hematology, mortality, blood donor characteristics

Brief summary

Red blood cell (RBC) transfusions are selected based upon matching donor and recipient blood group: donor and recipient sex are not considered when selecting blood for transfusion. Hence, transfused patients can currently receive sex-matched and/or unmatched RBCs when transfusions are given. Sex-matched stem cell transplants, and some solid organ transplants, have shown that sex-matching donor to recipient improves patient outcomes. Recent exploratory studies have also suggested that patient outcomes could be improved by sex-matching for RBC transfusion. There is emerging evidence of underlying biologic mechanism(s) to support these observations. This study is designed as a randomized controlled trial and will explore the impact on patients who receive RBC transfusions from donors of the same sex ("sex-matched") compared with donors of the opposite sex ("sex-mismatched"). The trial will study adult patients admitted to the Intensive Care Unit who require an RBC transfusion. Patients will be assigned (through a process called randomization) to receive sex-matched RBCs or sex-mismatched RBCs to determine if there is a difference in mortality between those receiving matched versus mismatched RBCs. The results of this trial could have direct implications on resources, blood inventory, and RBC transfusion ordering practices.

Detailed description

Background: Red blood cell (RBC) transfusions are selected based upon donor and recipient blood group compatibility without consideration of donor and recipient sex. Stem cell transplants, and some solid organ transplants, have shown that sex-matching donor to recipient improves patient outcomes. The Principal Investigator has completed a systematic review/meta-analysis and a 40,000 patient exploratory analysis; both showed a signal of benefit from sex-matched RBC transfusion. Biological findings to support the hypothesis that sex-matched RBC transfusions improve survival in recipients are also emerging. Controversial results have emerged from observational studies and a randomized controlled trial (RCT) regarding recipient mortality from sex-mismatched RBC transfusions; hence, equipoise exists. The Principal Investigator completed a multisite pilot RCT that showed feasibility for conducting a large-scale RCT and has helped to inform design for this study proposal. The goal of this research project is to develop a precision transfusion strategy based on sex-matching of blood donor and recipient to minimize adverse effects and improve patient outcomes post-transfusion. Overall Research Question: In transfused adult patients admitted to the Intensive Care Unit (ICU), do donor-recipient sex-matched RBC transfusions result in improved mortality compared to sex-mismatched RBC transfusions? Methods: This study is a superiority RCT with pragmatic features that will occur across participating sites in Canada. Study population: adult patients (age≥18) who are hospitalized with admission to an eligible ICU and requiring RBC transfusion. Intervention: donor-recipient sex-matched RBC transfusions. Comparison: donor-recipient sex-mismatched RBC transfusions. Primary Outcome: 30 day mortality from time of randomization. Secondary Outcomes: time to death, 30 day in-hospital mortality, 90 day mortality, hemoglobin and creatinine increment, ICU and hospital lengths of stay, number/type of transfused products and cost effectiveness analysis. Subgroup analyses will consider recipient sex, age, transfusion exposure, blood type, admitting diagnosis, baseline hemoglobin/creatinine. Expertise: The study team is uniquely positioned with extensive knowledge and expertise in transfusion medicine, research methodology, conduct of large pragmatic trials, and biostatistics. The study team will collaborate with Canadian Blood Services and experts in blood utilization, and operational modeling. This study is supported and endorsed by the Canadian Transfusion Trials Group. Importance & Outcomes: Anemia is common in critically ill patients; as many as 90% of patients will become anemic by the third day of their ICU admission. Between 20% and 40% of critically ill patients admitted to the ICU will require RBC transfusion; each patient will receive on average 2 to 5 RBC units. The Age of Blood Evaluation (ABLE) study showed a 90 day all cause mortality rate of 35-37% in the transfused ICU population studied. The pilot study reflected similar mortality rates. If providing sex-matched transfusions can decrease mortality, this could translate to high numbers of preventable deaths given that 85 million RBC units are transfused globally each year. If this study finds that donor-recipient sex-matching saves lives, this would require changes at the level of the blood supplier to identify sex on each RBC unit, and changes at the hospital level that would incorporate sex-matching into the selection of compatible blood for each patient.

Interventions

BIOLOGICALSex-mismatched red blood cell transfusions

Sex-mismatched red blood cell transfusions

BIOLOGICALSex-matched red blood cell transfusions

Sex-matched red blood cell transfusions

Sponsors

Michelle Zeller
Lead SponsorOTHER
Canadian Institutes of Health Research (CIHR)
CollaboratorOTHER_GOV

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Masking description

Site blood bank and transfusion officer.

Intervention model description

This study is a large scale, double-blind, superiority randomized control trial (RCT).

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Adults (age ≥18); * Admission to a participating ICU; * Requiring RBC transfusion.

Exclusion criteria

* Requirement for a specialized RBC product or unit not readily available in inventory (e.g., rare blood type, washed RBCs, complex RBC antibodies, etc.); * Massively bleeding patient (i.e., ≥4 units of blood ordered at one time, or Massive Hemorrhage Protocol initiated, or an urgent blood request made); * Sex unknown or sex other than male or female (i.e. intersex); * Do not have a valid Ontario Health Insurance Plan (OHIP) health card number.

Design outcomes

Primary

MeasureTime frameDescription
30 day mortalityFrom randomization to 30 days post-randomization.Death within 30 days of randomization.

Secondary

MeasureTime frameDescription
30 day in-hospital mortalityFrom randomization to 30 days post-randomization.In-hospital death within 30 days of randomization.
90 day mortalityFrom randomization to 90 days post-randomization.Death within 90 days of randomization.
Time to 30 day in-hospital mortalityFrom randomization to 30 days post-randomization.Time to in-hospital death within 30 days of randomization.
Hemoglobin incrementFrom time of randomization until death or discharge from ICU; up to 90 days post randomization.Lowest hemoglobin post-randomization during ICU admission.
Need for renal replacement therapyFrom time of randomization during ICU admission, until death or discharge from ICU; up to 90 days post randomization.Need for renal replacement therapy e.g. CRRT or HD post randomization during ICU admission.
ICU/hospital length of stayFrom randomization to 30 days post-randomization.The number of ICU-free days over 30 days and the number of days in hospital over 30 days.
Number/type/volume/dose of transfused productFrom randomization to 90 days post-randomization.Total number of transfusion interventions, cumulative proportion of units received that were from a sex-mismatched donor
Transfusion reactionsFrom randomization to 30 days post-randomization.Reactions related to RBC transfusions.
Cost effectivenessFrom randomization to 90 days post-randomization.Cost effectiveness measured using the incremental cost per life year saved (ICER) between sex-matched and mismatched transfusions.

Countries

Canada

Contacts

CONTACTMichelle Zeller, Doctor of Medicine
zeller@mcmaster.ca1-905-525-9140
CONTACTBambie Levoy-Jones, Honours Bachelor of Science
levoyjob@mcmaster.ca1-905-525-9140
PRINCIPAL_INVESTIGATORMichelle Zeller, Doctor of Medicine

McMaster University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 13, 2026