1 Department of Public Health, Vrije Universiteit Brussel, Brussel 1090, Belgium Coma Science Group, Cyclotron Research Centre and Neurology Department, University and University Hospital of Liège, Liège 4000, Belgium Critical Care Department and Cerebral Resuscitation Research Group, Centre for Neuroscience, University and University Hospital of Ghent, Gent 9000, Belgium Department of Anesthesiology, Vrije Universiteit Brussel, Brussel 1090, Belgium UZ Palliative and Supportive Care, Laarbeeklaan 101, 1090 Brussel, Belgium.