[1] Univ Toronto, Dept Surg, Toronto, ON, Canada
[2] Sunnybrook Hlth Sci Ctr, Div Gen Surg, Toronto, ON, Canada
[3] Sunnybrook Res Inst, Clin Evaluat Sci, Toronto, ON, Canada
[4] ICES, Toronto, ON, Canada
[5] Sunnybrook Hlth Sci Ctr, Dept Anesthesiol, Toronto, ON, Canada
[6] Univ Toronto, Dept Anesthesiol & Pain Med, Toronto, ON, Canada
[7] Univ Toronto, Dept Otolaryngol Head & Neck Surg, Toronto, ON, Canada
[8] Ctr Hosp Univ Montreal, Ctr Rech CHUM, Carrefour innovat & Sante populat, Montreal, PQ, Canada
[9] Ctr Hosp Univ Montreal, Dept Anesthesiol, Div Crit Care, Montreal, PQ, Canada
[10] Univ Montreal, Dept Anesthesiol & Pain Med, Montreal, PQ, Canada
[11] Univ Ottawa, Dept Anesthesiol, Ottawa, ON, Canada
[12] Univ Ottawa, Dept Pain Med, Ottawa, ON, Canada
[13] Ottawa Hosp, Ottawa, ON, Canada
[14] Univ Laval, Dept Anesthesiol & Crit Care Med, Div Crit Care Med, Quebec City, PQ, Canada
[15] Univ Laval, Res Ctr, CHU Quebec, Populat Hlth & Optimal Hlth Practices Res Unit,Tr, Quebec City, PQ, Canada
[16] Univ British Columbia, Dept Anesthesiol Pharmacol & Therapeut, Vancouver, BC, Canada
[17] Providence Hlth Care, St Pauls Hosp, Dept Anesthesiol, Vancouver, BC, Canada
[18] Toronto Western Hosp, Dept Anesthesiol, Toronto, ON, Canada
[19] Univ Hlth Network, Toronto Western Hosp, Wilson Ctr, Toronto, ON, Canada
[20] Womens Coll Hosp, Womens Coll Res Inst, Toronto, ON, Canada
[21] Univ Hlth Network, Dept Surg, Div Thorac Surg, Toronto, ON, Canada
[22] Univ Manitoba, Dept Surg, Winnipeg, MB, Canada
[23] Univ Manitoba, Sect Thorac Surg, Dept Community Hlth Sci, Winnipeg, MB, Canada
[24] Univ Toronto, Dalla Lana Sch Publ Hlth, Div Biostat, Toronto, ON, Canada