[1] Univ Witwatersrand, Fac Hlth Sci, Dept Internal Med, Johannesburg, South Africa
[2] Univ Witwatersrand, Fac Hlth Sci, Dept Crit Care, Johannesburg, South Africa
[3] Hebrew Univ Jerusalem, Fac Med, Hadassah Karem Med Ctr, Dept Anesthesiol Crit Care & Pain Med, Jerusalem, Israel
[4] Natl & Kapodistrian Univ Athens, Dept Intens Care Med 1, Evaggelsimos Gen Hosp, Med Sch, Athens, Greece
[5] Charite Univ Med Berlin, Berlin, Germany
[6] Free Univ Berlin, Berlin, Germany
[7] Humboldt Univ, Inst Biometry & Clin Epidemiol, Berlin, Germany
[8] Charite, Dept Anesthesiol & Intens Care Med, Berlin, Germany
[9] Univ Hosp Med Sch, Klin Bavaria, Ulm, Germany
[10] Univ Hosp Med Sch, Kreischa, Clin Anaesthesiol & Intens Care Med, Ulm, Germany
[11] Univ Hosp Southampton, Southampton, Hants, England
[12] Freeman Rd Hosp, Newcastle Upon Tyne, Tyne & Wear, England
[13] Univ Cadiz, Med Dept, INiBICA, Cadiz, Spain
[14] Univ Hosp Jerez, Intens Care Unit, Jerez de la Frontera, Spain
[15] Univ Francisco de Vitoria, ICU Hosp Univ Torrejon, Madrid, Spain
[16] Chinese Univ Hong Kong, Dept Anaesthesia & Intens Care, Fac Med, Hong Kong, Peoples R China
[17] Gabriel Montpied Univ Hosp, Med Intens Care Unit, Clermont Ferrand, France
[18] Paris & Descartes Univ, Intens Care Unit, St Louis Hosp La Rochelle, Paris, France
[19] Apss Trento, Comitato Etico Att Sanit, Trento, Italy
[20] IRCCS, Dipartimento Sci Emergenza Anestesiol & Rianimaz, Fdn Policlin Univ A Gemelli, Rome, Italy
[21] Univ Cattolica Sacro Cuore, Rome, Italy
[22] Semmelweis Univ, Dept Anesthesiol & Intens Care, Budapest, Hungary
[23] Stavanger Univ Hosp, Crit Care & Anaesthesiol Res Grp, Stavanger, Norway
[24] Univ Bergen, Dept Clin Med, Bergen, Norway
[25] Oslo Univ Hosp, Dept Res & Dev, Div Emergencies & Crit Care, Oslo, Norway
[26] Tata Med Ctr, Dept Crit Care, Kolkata, India
[27] Cleveland Clin Fdn, Anesthesiol Inst, Dept Intens Care & Resuscitat, 9500 Euclid Ave, Cleveland, OH 44195 USA
[28] Cleveland Clin Fdn, Anesthesiol Inst, Dept Outcome Res, 9500 Euclid Ave, Cleveland, OH 44195 USA
[29] Holbaek Cent Hosp, Dept Anaesthesiol & Intens Care, Holbaek, Sjaelland, Denmark
[30] Univ Porto, ICU Ctr Hosp Univ Porto, Porto, Portugal
[31] Univ Porto, Inst Ciencias Biomed Abel Salazar, Porto, Portugal
[32] Prince Charles Hosp, Intens Care Unit, Brisbane, Qld, Australia