1. Department of Palliative Medicine, University Hospital of Cologne, Cologne, Germany.
2. Institute for Medical Statistics, Informatics, and Epidemiology, University Hospital of Cologne, Cologne, Germany.
3. IMVR-Institute for Medical Sociology, Health Services Research and Rehabilitation Science, University Hospital of Cologne, Cologne, Germany.
4. Center for Integrated Oncology, University Hospital of Cologne, Cologne, Germany.
5. Clinical Trials Center, University Hospital of Cologne, Cologne, Germany.