Association of COVID-19 vs Influenza with Risk of Arterial and Venous Thrombotic Events Among Hospitalized Patients

The incidence of arterial thromboembolism and venous thromboembolism in persons with COVID-19 remains unclear. The objective of this study was to measure the 90-day risk of arterial thromboembolism and venous thromboembolism in patients hospitalized with COVID-19 before or during COVID-19 vaccine availability vs patients hospitalized with influenza. The authors conducted a retrospective cohort study of 41,443 patients hospitalized with COVID-19 before vaccine availability (April-November 2020), 44,194 patients hospitalized with COVID-19 during vaccine availability (December 2020-May 2021), and 8,269 patients hospitalized with influenza (October 2018-April 2019) in the US Food and Drug Administration Sentinel System (data from two national health insurers and four regional integrated health systems).