[1] Ottawa Hosp Res Inst, Clin Epidemiol Program, Ottawa, ON K1Y 4E9, Canada
[2] Univ Ottawa, Dept Family Med, Ottawa, ON, Canada
[3] Ctr Addict & Mental Hlth, Inst Mental Hlth Policy Res, Toronto, ON, Canada
[4] Univ Ottawa, Fac Med, Sch Epidemiol & Publ Hlth, Ottawa, ON, Canada
[5] Univ Toronto, Dalla Lana Sch Publ Hlth, Toronto, ON, Canada
[6] Western Univ, Dept Epidemiol & Biostat, London, ON, Canada