1. Faculty of Medicine and University Hospital of Cologne, Department of Anesthesiology and Intensive Care Medicine, University of Cologne, Cologne, Germany (CP, MN, HD, JH, WAW, BWB);
2. Faculty of Medicine and University Hospital of Cologne, Centre of Palliative Medicine, University of Cologne, Cologne, Germany (JL);
3. Faculty of Medicine, Institute of Medical Statistics and Computational Biology, University of Cologne, Cologne, Germany (SS);
4. Department of Anesthesiology and Intensive Care Medicine, Schön Klinik Düsseldorf, Düsseldorf, Germany (OS)