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Risk of Arterial and Venous Thrombotic Events Among Patients with COVID-19: A Multi-National Collaboration of Regulatory Agencies from Canada, Europe, and United States

    Basic Details

    Few studies have examined how the absolute risk of thromboembolism with COVID-19 has evolved over time across different countries. Researchers from the European Medicines Agency, Health Canada, and the United States (US) Food and Drug Administration established a collaboration to evaluate the absolute risk of arterial (ATE) and venous thromboembolism (VTE) in the 90 days after diagnosis of COVID-19 in the ambulatory (eg, outpatient, emergency department, nursing facility) setting from seven countries across North America (Canada, US) and Europe (England, Germany, Italy, Netherlands, and Spain) within periods before and during COVID-19 vaccine availability. We conducted cohort studies of patients initially diagnosed with COVID-19 in the ambulatory setting from the seven specified countries. Patients were followed for 90 days after COVID-19 diagnosis. The primary outcomes were ATE and VTE over 90 days from diagnosis date. We measured country-level estimates of 90-day absolute risk (with 95% confidence intervals) of ATE and VTE.


    Vincent Lo Re III, Noelle M. Cocoros, Rebecca A. Hubbard, Sarah K. Dutcher, Craig W. Newcomb, John G. Connolly, Silvia Perez-Vilar, Dena M. Carbonari, Maria E. Kempner, Andrew B. Petrone, Allyson M. Pishko, Meighan Rogers Driscoll, James T. Brash, Sean Burnett, Catherine Cohet, Matthew Dahl, Terese A. DeFor, Antonella Delmestri, Djeneba Audrey Djibo, Talita Duarte-Salles, Laura B. Harrington, Melissa Kampman, Jennifer L. Kuntz, Xavier Kurz, Nuria Mercade-Besora, Pamala A. Pawloski, Peter R. Reijnbeek, Sarah Seager, Claudia A. Steiner, Katia Verhamme, Fangyun Wu, Yunping Zhou, Edward Burn, J. Michael Paterson, Daniel Prieto-Alhambra

    Corresponding Author

    Vincent Lo Re III; Division of Infectious Diseases, Department of Medicine, Division of Epidemiology, Department of Biostatistics, Epidemiology, and Informatics, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA