[1] Univ Oxford, Nuffield Dept Populat Hlth, Clin Trial Serv Unit & Epidemiol Studies Unit CTSU, Oxford, England
[2] Univ Oxford, Nuffield Dept Populat Hlth, Epidemiol Studies Unit CTSU, Oxford, England
[3] Univ Toronto, Inst Hlth Policy Management & Evaluat, Toronto, ON, Canada
[4] Western Univ, Sch Phys Therapy, London, ON, Canada
[5] Western Univ, Westerns Bone & Joint Inst, London, ON, Canada
[6] Univ Western Ontario, Schulich Sch Med, London, ON N6A 3K7, Canada
[7] Univ Zurich, Med Fac, CH-8091 Zurich, Switzerland
[8] Univ Coll London, Inst Ophthalmol, Greater London, England
[9] Fac Amer FAM, Physiotherapy Dept, Sao Paulo, Brazil
[10] Oswaldo Cruz German Hosp, Hlth Technol Assessment Unit, Sao Paulo, Brazil
[11] Univ Toronto, Dalla Lana Sch Publ Hlth, Biostat Div, Toronto, ON, Canada
[12] McMaster Univ, Dept Anesthesia, Hamilton, ON, Canada
[13] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON, Canada
[14] Univ Leicester, Dept Populat Hlth Sci, Leicester, Leics, England
[15] Univ Ottawa, Fac Med, Dept Med, Ottawa, ON, Canada
[16] Ottawa Hosp Res Inst, Clin Epidemiol Program, Ottawa, ON, Canada
[17] Univ Toronto, Dept Med, Toronto, ON, Canada
[18] Univ Bern, Inst Primary Hlth Care BIHAM, Bern, Switzerland