[1] Sinai Hlth, Schwartz Reisman Emergency Med Inst, Toronto, ON, Canada
[2] Univ Toronto, Dept Family & Community Med, Div Emergency Med, 600 Univ Ave,Room 206, Toronto, ON M5G 1X5, Canada
[3] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON, Canada
[4] Ontario Hlth Canc Care Ontario, Minist Hlth, Toronto, ON, Canada
[5] Sunnybrook Res Inst, Toronto, ON, Canada
[6] McMaster Univ, Div Emergency Med, Dept Med, Hamilton, ON, Canada
[7] Univ Hosp Geneva, Div Gen Internal Med, Geneva, Switzerland
[8] Univ Hosp Geneva, Div Clin Epidemiol, Geneva, Switzerland
[9] McMaster Univ, Dept Med, Hamilton, ON, Canada