[1] Intens Care Natl Audit & Res Ctr, 24 High Holborn, London WC1V 6AZ, England
[2] London Sch Hyg & Trop Med, Dept Hlth Serv Res & Policy, London, England
[3] Oxford Univ Hosp NHS Fdn Trust, Dept Pharm, Oxford OX3 9DU, England
[4] Univ Oxford, Kadoorie Ctr Crit Care Res, Nuffield Dept Clin Neurosci, Oxford OX3 9DU, England
[5] Univ Bristol, Bristol Med Sch, 39 Whatley Rd, Bristol BS8 2PS, Avon, England
[6] UK Renal Registry, Brandon House,Bldg 20A1,Southmead Rd, Bristol BS34 7RR, Avon, England
[7] Univ Surrey, Fac Hlth Sci, Dept Clin & Expt Med, Guildford GU2 7XH, Surrey, England
[8] Royal Surrey Cty Hosp NHS Fdn Trust, Intens Care Unit, Guildford GU2 7XX, Surrey, England
[9] Oxford Univ Hosp NHS Fdn Trust, John Radcliffe Hosp, Oxford OX3 9DU, England
[10] Kings Coll London, Dept Crit Care, Guys & St Thomas Hosp, Westminster Bridge Rd, London SE1 7EH, England
[11] Univ Oxford, John Radcliffe Hosp, Kadoorie Ctr Crit Care Res & Educ, Oxford OX3 9DU, England
[12] Univ Oxford, John Radcliffe Hosp, Nuffield Dept Clin Neurosci, Level 6,West Wing, Oxford OX3 9DU, England
[13] Oxford Univ Hosp NHS Trust, NIHR Biomed Res Ctr, Kadoorie Ctr Crit Care Res & Educ, Headley Way, Oxford OX3 9DU, England