[1] Ottawa Gen Hosp, Div Hematol, Ottawa Hlth Res Inst, Clin Epidemiol Unit, Ottawa, ON K1H 8L6, Canada
[2] Univ Ottawa, Dept Med, Div Hematol, Thrombosis Program, Ottawa, ON, Canada
[3] Brest Univ Hosp, Dept Internal Med & Chest Dis, Brest, France
[4] Univ Western Ontario, Dept Med, Div Hematol, London, ON, Canada
[5] McGill Univ, Dept Med, Montreal, PQ, Canada
[6] McGill Univ, Jewish Gen Hosp, Ctr Clin Epidemiol & Community Studies, Montreal, PQ H3T 1E2, Canada
[7] Dalhousie Univ, Dept Med, Halifax, NS, Canada
[8] Univ Montreal, Dept Med, Hop Sacre Coeur, Montreal, PQ H3C 3J7, Canada
[9] McMaster Univ, Dept Med, Michael G DeGroote Sch Med, Hamilton, ON, Canada
[10] Univ Hosp Geneva, Dept Internal Med, Geneva, Switzerland
[11] UC Davis Sch Med, Dept Med, Sacramento, CA USA
[12] Univ British Columbia, Dept Med, St Pauls Hosp, Vancouver, BC, Canada
[13] Brest Univ Hosp, EA 3878, Brest, France