[1] Dalhousie Univ, Dept Emergency Med, Halifax, NS, Canada
[2] Dalhousie Univ, Div Crit Care Med, Dept Internal Med, Halifax, NS, Canada
[3] Univ Alberta, Dept Emergency Med, Edmonton, AB, Canada
[4] Univ Toronto, Div Emergency Med, Toronto, ON M5S 1A1, Canada
[5] St Michaels Hosp, Toronto, ON M5B 1W8, Canada
[6] Queens Univ, Kingston, ON, Canada
[7] Kingston Gen Hosp, Dept Emergency Med, Kingston, ON K7L 2V7, Canada
[8] St Pauls Hosp, Dept Emergency Med, Vancouver, BC V6Z 1Y6, Canada
[9] Univ Saskatchewan, Regina, SK, Canada
[10] Regina QuAppelle Hlth Reg, Dept Internal Med, Regina, SK, Canada
[11] Regina QuAppelle Hlth Reg, Dept Emergency Med, Regina, SK, Canada
[12] Hlth Sci Ctr, Dept Emergency Med, Winnipeg, MB, Canada