Department of Public Health, Erasmus MC University Medical Centre Rotterdam, Rotterdam, Netherlands. Australian and New Zealand Intensive Care Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia; Department of Intensive Care and Hyperbaric Medicine, The Alfred, Melbourne, VIC, Australia. School of Medicine and Surgery, University of Milano-Bicocca, Monza, MB, Italy; Neurointensive Care Unit, San Gerardo Hospital, ASST-Monza, Monza, MB, Italy. Department of Intensive Care Medicine, University Hospital of North Norway, Tromsø, Norway; UiT The Arctic University of Norway, Tromsø, Norway. Department of Neurology, Neurocritical Care, Medical University of Innsbruck, Anichstrasse, Innsbruck, Austria. Department of Neurosurgery, Antwerp University Hospital and University of Antwerp, Edegem, Belgium. Division of Anaesthesia, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK. Transfusion Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia. Neuroscience Intensive Care Unit, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy. Department of Neurology, Erasmus University Medical Center, Rotterdam, Netherlands. Department of Public Health, Erasmus MC University Medical Centre Rotterdam, Rotterdam, Netherlands; Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, Netherlands. Department of Intensive Care Adults, Erasmus MC - University Medical Center, Rotterdam, Netherlands. Electronic address: m.vanderjagt@erasmusmc.nl.