[1] Univ Ottawa, Fac Med, Ottawa, ON, Canada
[2] McMaster Univ, Dept Radiol, Hamilton, ON, Canada
[3] Ottawa Hosp, Res Inst, Ottawa, ON, Canada
[4] Univ Amsterdam, Acad Med Ctr, Dept Clin Epidemiol Biostat & Bioinformat, Amsterdam, Netherlands
[5] Ottawa Hosp, Res Inst, Clin Epidemiol Program, Ottawa, ON, Canada
[6] McGill Univ, Jewish Gen Hosp, Lady Davis Inst, Montreal, PQ, Canada
[7] McGill Univ, Dept Psychiat, Montreal, PQ, Canada
[8] Univ Ottawa, Ottawa Hosp, Clin Epidemiol Program, Dept Radiol,Res Inst, Room c159,Civ Campus,1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada