[1] Ottawa Hosp Res Inst, Clin Epidemiol Program, Ottawa, ON, Canada
[2] Yale Sch Publ Hlth, Dept Social & Behav Sci, New Haven, CT USA
[3] Univ Ottawa, Sch Epidemiol & Publ Hlth, Ottawa, ON, Canada
[4] Univ Alberta, Fac Law, Edmonton, AB, Canada
[5] Univ Alberta, Sch Publ Hlth, Edmonton, AB, Canada
[6] Univ Regina, Hill Levene Sch Business, Dept Psychol, Regina, SK, Canada
[7] Univ British Columbia, Sch Populat & Publ Hlth, Vancouver, BC, Canada
[8] EKOS Res Associates Inc, Publ Opin Res, Ottawa, ON, Canada
[9] Univ Ottawa, Dept Pediat, Ottawa, ON, Canada
[10] Univ Ottawa, Dept Med, Ottawa, ON, Canada
[11] Bruyere Res Inst, Ottawa, ON, Canada
[12] Ottawa Hosp, Clin Epidemiol Program, Civ Campus,Adm Serv Bldg,1053 Carling Ave, Ottawa, ON K1Y 4E9, Canada