1. Department of Medicine University of Toronto Toronto ON Canada
2. Department of Pathology Harvard Medical School Massachusetts General Hospital Boston MA USA
3. Department of Pathology University of Utah Salt Lake City UT USA
4. ARUP Laboratories, Hemostasis/Thrombosis Laboratory Salt Lake City UT USA
5. ECAT FoundationExternal Quality Control for Assays and Tests Voorschoten the Netherlands
6. Department of Laboratory Medicine and Medicine University of Toronto Toronto ON Canada