[1] Publ Hlth Ontario, Dept Hlth Promot Chron Dis & Injury Prevent, Toronto, ON, Canada
[2] Univ Toronto, Dalla Lana Sch Publ Hlth, Toronto, ON, Canada
[3] BC Childrens Hosp, British Columbia Injury Res & Prevent Unit, Vancouver, BC, Canada
[4] Univ British Columbia, Dept Pediat, Vancouver, BC, Canada
[5] York Univ, Fac Hlth, Toronto, ON, Canada
[6] 480 Univ Ave Su 300, Toronto, ON M5G 1A4, Canada