Non-White Race/Ethnicity and Female Sex Are Associated with Increased Allogeneic Red Blood Cell Transfusion in Cardiac Surgery Patients: 2007-2018

OBJECTIVE: To evaluate racial and/or ethnic and sex disparities in allogeneic and autologous red blood cell (RBC) transfusions in cardiac surgery.

DESIGN: A retrospective observational study.

SETTING: 2007 to 2018 data from FL, MD, KY, WA, NY, and CA from the State Inpatient Databases (SID), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

PARTICIPANTS: A total of 710,296 inpatients who underwent elective or emergency coronary artery bypass grafting (CABG), cardiac valve surgery,or combination CABG and/or valve surgery.

INTERVENTIONS: None.

MEASUREMENTS AND MAIN RESULTS: Patients were cohorted by race and/or ethnicity and sex, as defined by SID-HCUP. Demographic characteristics and comorbidities were compared. Rates and risk-adjusted odds ratios (aOR) were calculated for allogeneic and autologous RBC transfusion (primary outcomes). Additional secondary analyses were conducted for in-hospital mortality, 30-day readmission, 90-day readmission, hospital length of stay, and total charges to examine the effect of RBC transfusion status. Effect modification between race and sex was assessed. When controlling for patient demographics, comorbidities, and hospital characteristics, non-White patients were more likely to receive an allogeneic RBC transfusion during cardiac surgery than White patients (Black: aOR 1.17, 99% CI 1.13-1.20, p < 0.001, Hispanic: aOR 1.22, 99% CI 1.19-1.22, p < 0.001). Women were more likely to receive allogeneic RBC than men (aOR 1.69, 99% CI 1.66-1.72, p < 0.001). In interaction models, non-White women had the highest odds of allogeneic blood transfusion as compared to White men (reference category; Black women: aOR 2.04, 99% CI 1.91-2.17, p < 0.001, Hispanic women: aOR 2.03, 99% CI 1.90-2.16, p < 0.001).

CONCLUSION: These findings highlighted the differences in the rates of allogeneic RBC transfusion for non-White and female patients undergoing cardiac surgery, which is a well-established marker of poorer outcomes.