[1] Univ Montreal, Hop Sacre Coeur Montreal, Montreal, PQ, Canada
[2] Univ Toronto, Hosp Sick Children, Dalla Lana Sch Publ Hlth, Toronto, ON M5G 1X8, Canada
[3] Univ Toronto, Dept Med, Univ Hlth Network, Toronto, ON, Canada
[4] Univ Toronto, Dalla Lana Sch Publ Hlth, Toronto, ON, Canada
[5] Queens Univ, Kingston, ON, Canada
[6] Monash Univ, Dept Epidemiol & Prevent Med, Melbourne, Vic 3004, Australia