[1] Sunnybrook Hlth Sci Ctr, Sunnybrook Res Inst, Dept Crit Care Med, Toronto, ON M4N 3M5, Canada
[2] Univ Toronto, Interdept Div Crit Care, Toronto, ON, Canada
[3] Queens Univ, Dept Med, Kingston, ON K7L 3N6, Canada
[4] Kingston Gen Hosp, Clin Evaluat Res Unit, Kingston, ON K7L 2V7, Canada
[5] Univ Calgary, Dept Crit Care Med, Calgary, AB, Canada
[6] Alberta Hlth Serv, Calgary, AB, Canada
[7] Univ Calgary, Dept Community Hlth Sci, Calgary, AB, Canada
[8] Univ Calgary, Inst Publ Hlth, Calgary, AB, Canada
[9] Ctr Hlth Evaluat & Outcome Sci, Vancouver, BC, Canada
[10] Providence Hlth Care, Dept Med, Vancouver, BC, Canada
[11] Univ British Columbia, Vancouver, BC V5Z 1M9, Canada
[12] McMaster Univ, Dept Med, Hamilton, ON, Canada
[13] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada
[14] Sunnybrook Hlth Sci Ctr, Toronto, ON M4N 3M5, Canada
[15] Winnipeg Reg Hlth Author, Winnipeg, MB, Canada
[16] Queens Univ, Dept Community Hlth & Epidemiol, Kingston, ON, Canada
[17] St Michaels Hosp, Li Ka Shing Knowledge Inst, Toronto, ON M5B 1W8, Canada
[18] Univ Toronto, Dept Med, Toronto, ON, Canada
[19] Univ Ottawa, Childrens Hosp Eastern Ontario, Dept Crit Care Med, Ottawa, ON, Canada
[20] Univ Manitoba, Dept Med, Winnipeg, MB, Canada
[21] Univ Manitoba, Dept Community Hlth Sci, Winnipeg, MB R3T 2N2, Canada