[1] McMaster Univ, Grad Program Hlth Res Methodol, Hamilton, ON, Canada
[2] McMaster Univ, Dept Physiotherapy, Hamilton, ON, Canada
[3] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON, Canada
[4] Victoria Hosp, London Hlth Sci Ctr, Dept Crit Care Med, London, ON N6A 4G5, Canada
[5] Univ Toronto, Interdepartmental Div Crit Care, Toronto, ON, Canada
[6] Hamilton Gen Hosp, Dept Crit Care Med, Hamilton, ON, Canada
[7] Ottawa Gen Hosp, Dept Crit Care Med, Ottawa, ON K1H 8L6, Canada
[8] St Josephs Hosp, Dept Crit Care Med, Hamilton, ON, Canada