[1] Univ Ottawa, Dept Med, Ottawa Hosp Res Inst, Ottawa, ON K1H 8L6, Canada
[2] Univ Western Ontario, Dept Med, London, ON, Canada
[3] Univ Western Ontario, Dept Oncol, London, ON, Canada
[4] Univ Western Ontario, Dept Epidemiol & Biostat, London, ON, Canada
[5] Dalhousie Univ, Dept Med, Hlth Sci Ctr QE2, Halifax, NS, Canada
[6] Sir Mortimer B Davis Jewish Hosp, Lady Davis Inst Med Res, Ctr Clin Epidemiol, Dept Med, Montreal, PQ H3T 1E2, Canada
[7] McMaster Univ, Dept Med, Thrombosis & Atherosclerosis Res Inst, Hamilton, ON, Canada
[8] Ctr Hosp Univ Montreal, Dept Med, Montreal, PQ, Canada
[9] Univ Alberta, Dept Oncol, Edmonton, AB, Canada
[10] McMaster Univ, St Josephs Hosp, Hamilton, ON, Canada
[11] McMaster Univ, Dept Pathol & Mol Med, Hamilton, ON, Canada