1. Department of Palliative Medicine, University Medical Center Göttingen, Germany.
2. Department of Palliative Medicine and Clinical Trials Unit Palliative Medicine, University Hospital Cologne, Germany.
3. Institut für Palliative Care, Oldenburg, Germany.
4. Institute for Mathematical Stochastics, University of Goettingen, Germany.
5. Clinical Research and Application, Kleinmachnow, Germany.