1 Susan R. Kahn, MD MSc FRCPC, Centre of Excellence in Thrombosis and Anticoagulation Care, Division of Internal Medicine & Center for Clinical Epidemiology, Jewish General Hospital, 3755 Cote Ste. Catherine Room H420.1, Montreal, H3T 1E2 QC, Canada, Tel.: +1 514 340 7587, Fax: +1 514 340 7564, E-mail: susan.kahn@mcgill.ca.