Predictors of Red Blood Cell Transfusion in Elderly COVID-19 Patients in Korea.

Background: Patients who experience clinical deterioration from coronavirus disease (COVID-19) require blood transfusion support. We analyzed blood component usage in COVID-19 patients and identified the predictors of red blood cell (RBC) transfusion in elderly (≥65 years) patients. Methods: Blood component usage in 882 COVID-19 patients hospitalized between January 24, 2020 and April 30, 2021 was analyzed. Elderly patients were categorized into transfused and non-transfused groups according to their RBC transfusion history; their demographic and clinical characteristics, disease severity, and outcomes were compared. Associations were determined using multiple logistic regression. Results: The overall transfusion rate was 8.3% (73/882), and the transfusion rate was 2.7% (14/524) in patients aged <65 years and 16.5% (59/358) in those aged ≥65 years. Among the 358 elderly patients, 344 patients, including 50 who received transfusion and 294 who did not, were enrolled for the analysis. The prevalence of diabetes mellitus (DM), white blood cell count, absolute neutrophil count, and neutrophil-to-lymphocyte ratio (NLR) on admission were significantly higher in the transfused group, whereas Hb and platelet counts were significantly lower. Disease severity in the transfused group was relatively high on admission and increased thereafter. DM, intensive care unit entrance on admission, Hb, platelet count, and NLR on admission were independently associated with RBC transfusion. Conclusions: This study presents transfusion rates in COVID-19 patients according to age groups and predictors of RBC transfusion in elderly patients. The results provide a basis for developing a strategy for the medical treatment of infectious diseases emerging during pandemics.