[1] Univ Ottawa, Childrens Hosp, Eastern Ontario Res Inst, Dept Pediat, Ottawa, ON, Canada
[2] Univ Ottawa, Sch Epidemiol Publ Hlth & Prevent Med, Ottawa, ON, Canada
[3] Inst Clin Evaluat Sci, Toronto, ON, Canada
[4] London Sch Hyg & Trop Med, London, England
[5] Univ Toronto, Hosp Sick Children, Dept Paediat, Toronto, ON, Canada
[6] Univ Toronto, Inst Hlth Policy Management & Evaluat, Toronto, ON, Canada
[7] Univ Hosp Basel, Basel Inst Clin Epidemiol & Biostat, Basel, Switzerland
[8] Ottawa Hosp, Res Inst, Ottawa, ON, Canada
[9] Univ Ottawa, Sch Epidemiol Publ Hlth & Preventat Med, Ottawa, ON, Canada
[10] UCL, Dept Primary Care & Populat Hlth, London, England
[11] Aarhus Univ, Dept Clin Epidemiol, Aarhus, Denmark
[12] Univ Med Ctr Lausanne, Cochrane Switzerland, Inst Social & Prevent Med, Lausanne, Switzerland