[1] CHU Quebec, Res Ctr, Quebec City, PQ, Canada
[2] Univ Laval, Dept Family Med & Emergency Med, Quebec City, PQ, Canada
[3] Ottawa Hosp, Clin Epidemiol Program, Res Inst, Ottawa, ON, Canada
[4] Univ Ottawa, Sch Epidemiol Publ Hlth & Prevent Med, Ottawa, ON, Canada