[1] Univ Western Ontario, Dept Epidemiol & Biostat, Schulich Sch Med & Dent, London, ON, Canada
[2] Univ Western Ontario, Dept Med, Div Nephrol, London, ON, Canada
[3] Univ Toronto, Inst Clin Evaluat Sci, Toronto, ON, Canada
[4] Univ Toronto, Div Nephrol, Toronto, ON, Canada
[5] Univ Ottawa, Div Nephrol, Kidney Res Ctr, Ottawa Hosp,Res Inst, Ottawa, ON, Canada
[6] Ottawa Hosp, Res Inst, Clin Epidemiol Program, Ottawa, ON, Canada
[7] St Louis Univ, Ctr Outcomes Res, St Louis, MO 63103 USA
[8] McGill Univ, Ctr Hlth, Div Nephrol, Montreal, PQ, Canada
[9] McMaster Univ, Dept Med, Div Nephrol, Hamilton, ON, Canada