Blood Transfusion Utilization in Patients with Severe Coronavirus Disease 2019 in the Republic of Korea: A Nationwide Population-Based Study.

: The coronavirus disease 2019 (COVID-19) pandemic has significantly affected both supply and demand for blood transfusion. This study aimed to investigate the prescription patterns of blood products and identify the risk factors for blood transfusion in patients with severe COVID-19. : This nationwide population-based cohort study was performed in the Republic of Korea between January 2021 and December 2021. Adult patients (≥19 years) with severe COVID-19 who received oxygen therapy were examined. Data were obtained from the National Health Insurance Service database. : During the study period, 41,203 patients developed severe COVID-19. The overall transfusion rate was 7.11%, with 14,477 units of packed red blood cells, 4501 units of fresh frozen plasma, 20,532 units of platelet concentrates, and 1875 units of cryoprecipitate. Blood transfusion was independently associated with 90-day mortality (hazard ratio: 1.36, 95% confidence interval: 1.21-1.53, < 0.001). Multivariate logistic regression analysis identified underlying chronic kidney disease; exposure to surgery, thrombolysis, or thrombectomy; renal replacement therapy; mechanical ventilation; and extracorporeal membrane oxygenation as significant risk factors for blood transfusion in patients with severe COVID-19. Conversely, underlying cerebrovascular diseases, a Charlson Comorbidity Index score of ≥6, admission to intensive care units, and anticoagulant use were identified as protective factors. : This study provides an overview of blood transfusion patterns in patients with severe COVID-19. Understanding these patterns may help optimize the stockpiling of medical resources.