[1] Univ Western Ontario, Schulich Sch Med & Dent, London, ON, Canada
[2] Univ Toronto, Dept Family & Community Med, Toronto, ON M5S 1A1, Canada
[3] Univ Toronto, Inst Clin Evaluat Sci, Toronto, ON M5S 1A1, Canada
[4] Univ Toronto, Li Ka Shing Knowledge Inst, Dalla Lana Sch Publ Hlth, St Michaels Hosp, Toronto, ON, Canada
[5] St Michaels Hosp, Div Gen Internal Med, Toronto, ON M5B 1W8, Canada
[6] St Michaels Hosp, Li Ka Shing Knowledge Inst, Keenan Res Ctr, Toronto, ON M5B 1W8, Canada
[7] Univ Toronto, Dept Med, Toronto, ON, Canada
[8] Univ Toronto, St Michaels Hosp, Dept Med, Toronto, ON M5B 1W8, Canada
[9] Univ Toronto, St Michaels Hosp, Dept Obstet & Gynecol, Toronto, ON, Canada
[10] Univ Toronto, St Michaels Hosp, Dept Hlth Policy Management & Evaluat, Toronto, ON, Canada