[1] Univ Calgary, Dept Crit Care Med, Foothills Med Ctr, Ground Floor McCaig Tower,1403-29 St NW, Calgary, AB T2N 5A1, Canada
[2] Univ Calgary, Dept Community Hlth Sci, Cumming Sch Med, 3D10,3280 Hosp Dr NW, Calgary, AB T2N 4Z6, Canada
[3] Univ Calgary, OBrien Inst Publ Hlth, Cumming Sch Med, 3rd Floor TRW Bldg,3280 Hosp Dr NW, Calgary, AB T2N 4Z6, Canada
[4] Univ Calgary, W21C Res & Innovat Ctr, Cumming Sch Med, GD01-TRW Bldg,3280 Hosp Dr NW, Calgary, AB T2N 4Z6, Canada
[5] McMaster Univ, Med Ctr, Dept Med, 1200 Main St West, Hamilton, ON L8N 3Z5, Canada
[6] McMaster Univ, Med Ctr, Dept Clin Epidemiol & Biostat, 1200 Main St West, Hamilton, ON L8N 3Z5, Canada
[7] Univ Toronto, Inst Hlth Policy Management & Evaluat, 155 Coll St,Suite 425, Toronto, ON M5T 3M6, Canada
[8] St Michaels Hosp, Keenan Res Ctr, Li Ka Shing Knowledge Inst, 30 Bond St,Shuter 2-026, Toronto, ON M5B 1W8, Canada
[9] Univ Alberta, Dept Crit Care Med, Fac Med & Dent, 2-124E Clin Sci Bldg,8440-112 St NW, Edmonton, AB T6G 2B7, Canada
[10] Univ Alberta, Sch Publ Hlth, 2-124E Clin Sci Bldg,8440-112 St NW, Edmonton, AB T6G 2B7, Canada
[11] Univ Alberta, Sch Publ Hlth, Edmonton Clin Hlth Acad 3 300, 11405-87 Ave, Edmonton, AB T6G 1C9, Canada