Risk of Admission to Hospital with Arterial or Venous Thromboembolism Among Patients Diagnosed in the Ambulatory Setting with COVID-19 Compared with Influenza: Retrospective Cohort Study

Studies evaluating thrombotic complications with COVID-19 have focused mainly on patients admitted to hospital. In this retrospective cohort study, we measured the 90-day risk of arterial thromboembolism and venous thromboembolism among patients diagnosed with COVID-19 in the ambulatory (i.e., outpatient, emergency department, or institutional) setting during periods before and during covid-19 vaccine availability and compared results to patients with ambulatory diagnosed influenza.