Medicare and Medicaid insurance status is associated with increased allogeneic red blood cell transfusion in cardiac surgery patients: 2007-2018

Background and Aim Allogeneic red blood cell (RBC) transfusion and health insurance status are independently associated with perioperative morbidity. The aim of this study was to evaluate the effect of insurance status on allogeneic and autologous transfusion risk in cardiac surgery patients. Methods We conducted a retrospective observational study of data spanning 2007-2018 from six states from the State Inpatient Databases. Patients were cohorted by medical insurance type. Rates and risk-adjusted odds ratios (aOR) were calculated for allogenic and autologous RBC transfusions. Interactions between insurance and race/ethnicity were assessed. Results A total of 710,296 cardiac surgery patients were included. Allogeneic infusions occurred in 34.7% of Medicare patients, 31.9% of Medicaid patients, 24.7% of privately insured patients, and 26.1% of uninsured patients. Autologous rates were 2.3%, 2.5%, 3.4%, and 2.6% for Medicare, Medicaid, privately insured, and uninsured patients, respectively. Medicare and Medicaid patients were more likely to receive allogeneic RBC than privately insured patients (Medicare: aOR: 1.42, 99% confidence interval [CI]: 1.40-1.44, p < .001, Medicaid: aOR: 1.18, 99% CI: 1.14-1.21, p < .001). Nonwhite Medicare patients showed higher odds of allogeneic transfusion compared with White patients with private insurance (Black Medicare: aOR 1.74, 99% CI: 1.65-1.83, p < .001, Hispanic Medicare: aOR 1.92, 99% CI: 1.84-2.00, p < .001). Conclusion Cardiac surgery patients with Medicare and Medicaid insurance demonstrate increased risk of allogeneic RBC transfusion; nonwhite patient groups are particularly vulnerable. Further research is needed to understand the causes and implications of these disparities, and to help ensure equitable care across patient groups.