[1] Univ Toronto, Dept Med, Univ Hlth Network, Toronto, ON, Canada
[2] Univ Toronto, Interdept Div Crit Care, Toronto, ON, Canada
[3] Univ Toronto, Dept Publ Hlth Sci, Toronto, ON, Canada
[4] Univ Toronto, Sunnybrook Hlth Sci Ctr, Dept Crit Care Med, Toronto, ON, Canada
[5] Univ Toronto, Sunnybrook Hlth Sci Ctr, Dept Anesthesia, Toronto, ON, Canada
[6] Univ Toronto, St Michaels Hosp, Dept Anesthesia, Toronto, ON M5B 1W8, Canada
[7] Univ Toronto, St Michaels Hosp, Dept Med & Crit Care Med, Toronto, ON M5B 1W8, Canada
[8] Univ Toronto, St Michaels Hosp, Li Ka Shing Knowledge Inst, Keenan Res Ctr, Toronto, ON M5B 1W8, Canada
[9] Univ Toronto, Mt Sinai Hosp, Dalla Lana Sch Publ Hlth, Toronto, ON M5G 1X5, Canada
[10] Univ Toronto, Mt Sinai Hosp, Dept Med, Toronto, ON M5G 1X5, Canada
[11] Univ Toronto, Mt Sinai Hosp, Dept Anesthesia, Toronto, ON M5G 1X5, Canada
[12] McMaster Univ, Dept Med, Hamilton, ON, Canada
[13] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada