Background: In 2020, convalescent plasma (CP) was authorized for the treatment of hospitalized patients with COVID-19. Assessment of real-world use of CP is needed to understand transfusion demand during pandemic.
Objectives: To evaluate CP use among transfused inpatient fee-for-service Medicare beneficiaries age 65+ with COVID-19 during April 2020-December 2021.
Methods: This retrospective study used Medicare data; with revenue center, procedure, and diagnosis codes to identify transfusions, blood components, and COVID-19 status. We assessed overall and monthly use prevalence of CP only, CP transfusion combination, and non-CP transfusions per 100 COVID-19 inpatient transfusion stays. Results were stratified by immunocompromised (IC) status, demographic characteristics, U.S. Census Regions, and severity measures.
Results: Among 1,569,398 inpatient transfusion stays, 183,335 (11.7%) had COVID-19. Among COVID-19 transfusion stays, 45.1% received CP only, 3.1% CP with other blood component(s), and 51.8% non-CP transfusions. In comparison, < 0.02% of non-COVID-19 stays received CP. Among transfusion stays with COVID-19, prevalence of CP only use was: 48.2% vs. 28.8% for non-IC vs. IC; 47.1% vs. 43.0% for males vs. females; 48.6% vs. 32.4% for white vs. non-white; 44.9% vs. 45.6% for 65-79 vs. 80+; 49.2% vs. 34.3% for non- vs. Medicaid eligible; 51.1% vs. 43.4% for rural vs. urban residents; and 30.0%, 41.9%, 48.5%, and 49.1% for Northeast, West, South, and Midwest residents, respectively. Monthly use prevalence of CP only increased from August 2020 (39.4%) through October 2020 (66.8%), and then declined from November 2020 (66.3%) through December 2021 (5.3%). Inpatient COVID-19 stays with CP only vs. CP transfusion combination vs. non-CP transfusions had: length of stay (LOS)>10 days (41.7% vs. 75.3% vs. 57.4%), mechanical ventilation (17.8% vs. 52.2% vs. 32.6%) and inpatient mortality (25.7% vs. 52.5% vs. 32.9%).
Conclusions: Our investigation shows substantial use of CP among transfused inpatients aged 65+ with COVID-19 and rare use in non-COVID-19 patients. CP use was highest during October and November of 2020 with substantial decline through end of 2021. CP only use prevalence was higher for males vs. females, whites vs. non-whites, non-IC vs. IC, non- vs. Medicaid eligible, rural vs. urban, and residents of the South and Midwest vs. West and Northeast. The findings showed lower rates of inpatient mortality, mechanical ventilation, and shorter LOS for CP only users suggesting lower COVID-19 severity. Overall, differences identified in CP utilization may be due to variations in COVID-19 severity, comorbidities, availability, access to care, and health seeking behaviors that need future evaluation.
