[1] Hosp Sick Children, Div Paediat Emergency Med, Toronto, ON M5G 1X8, Canada
[2] King Abdulaziz Univ, Fac Med, Dept Paediat, Jeddah 21413, Saudi Arabia
[3] Univ Toronto, St Josephs Hlth Ctr, Toronto, ON, Canada
[4] Hosp Sick Children, Div Emergency Med, Toronto, ON M5G 1X8, Canada
[5] McMaster Childrens Hosp, Fac Hlth Sci, Dept Pediat, Div Pediat Emergency Med, Hamilton, ON, Canada
[6] Univ Montreal, Dept Pediat, Secteur Urgence, CHU St Justine Univ Hosp Ctr, Montreal, PQ H3C 3J7, Canada
[7] Univ Toronto, Dept Paediat, Toronto, ON M5S 1A1, Canada