1. Division of Hematology, Department of Medicine, Duke University, Durham NC;
2. Pontificia Universidad Catolica de Chile, Santiago, Chile;
3. Department of Medicine and Surgery, University of Insurbria, Varese, Italy;
4. Division of General Internal Medicine, Department of Medicine, University of Florida, Gainesville, FL;
5. Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL;
6. Clinical Pharmacy Anticoagulation Service, Kaiser Permanente, Aurora, CO;
7. Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA;
8. Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands;
9. Harvard Medical School, Boston, MA;
10. University of California Davis, Sacramento, CA;
11. Veterans Affairs Northern California Health Care System, Mather, CA;
12. Department of Medicine, Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton, ON, Canada;
13. Department of Obstetrics and Gynecology, I.M. Sechenov First Moscow State Medical University, Moscow, Russia;
14. May-Thurner Syndrome Resource Network;
15. Division of Diagnostic Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO;
16. KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium;
17. Department of Pharmacotherapy, College of Pharmacy, University of Utah, Salt Lake City, UT;
18. Department of Pediatrics, University of Antioquia, Medellin, Colombia;
19. Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada;
20. Internal Medicine Department, German Hospital, Buenos Aires, Argentina; and
21. Department of Medicine, McMaster University, Hamilton, ON, Canada