1. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, United States
2. National Blood Clot Alliance, Vienna, Virginia, United States
3. Hemophilia and Thrombosis Center, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States
4. Division of Hematology/Oncology, Department of Medicine, Larner College of Medicine at the University of Vermont, Burlington, Vermont, United States
5. Department of Pathology and Laboratory Medicine, Larner College of Medicine at the University of Vermont, Burlington, Vermont, United States