[1] Univ Ottawa, Dept Emergency Med, Ottawa, ON, Canada
[2] Ottawa Hosp Res Inst, Clin Epidemiol Program, Ottawa, ON, Canada
[3] Univ Ottawa, Sch Epidemiol & Publ Hlth, Ottawa, ON, Canada
[4] Western Univ, Lawson Hlth Res Inst, Schulich Sch Med & Dent, Dept Med,Div Emergency Med, London, ON, Canada
[5] Queens Univ, Dept Emergency Med, Kingston, ON, Canada
[6] Queens Univ, Dept Biomed & Mol Sci, Kingston, ON, Canada
[7] Univ Toronto, Schwartz Reisman Emergency Med Inst, Dept Family & Community Med, Sinai Hlth Syst, Toronto, ON, Canada
[8] Univ Laval, Dept Med Familiale & Urgence, Quebec City, PQ, Canada
[9] Univ Calgary, Dept Emergency Med, Calgary, AB, Canada
[10] Univ Calgary, Dept Community Hlth Sci, Calgary, AB, Canada