[1] Intens Care Natl Audit & Res Ctr, Clin Trials Unit, London, England
[2] Newcastle Upon Tyne Hosp NHS Fdn Trust, Freeman Hosp, Newcastle Upon Tyne, Tyne & Wear, England
[3] Newcastle Univ, Newcastle Clin Trials Unit, Newcastle Upon Tyne, Tyne & Wear, England
[4] Newcastle Univ, Inst Hlth & Soc, Newcastle Upon Tyne, Tyne & Wear, England
[5] Kingston Gen Hosp, Clin Evaluat Res Unit, Kingston, ON, Canada
[6] Queens Univ, Sch Med, Dept Crit Care Med, Kingston, ON, Canada