1. Department of Intensive Care Medicine and Brain Center Rudolf Magnus; University Medical Center Utrecht; Utrecht The Netherlands
2. Department of Intensive Care Medicine; Radboud University Medical Center Nijmegen; Nijmegen The Netherlands
3. Section of Geriatrics; Department of Internal Medicine; Isala Hospital; Zwolle The Netherlands
4. Department of Epidemiology; Julius Center for Health Sciences and Primary Care; University Medical Center Utrecht; Utrecht The Netherlands