1. Department of Palliative Medicine, Faculty of Medicine and University Hospital, University of Cologne, Germany
2. Cologne Graduate School in Management, Economics and Social Sciences, University of Cologne, Germany
3. Department of Educational and Social Sciences, University of Education Heidelberg, Germany
4. Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf, Faculty of Medicine and University Hospital, University of Cologne, Germany
5. Clinical Trials Center (ZKS), Faculty of Medicine and University Hospital, University of Cologne, Germany
6. Center for Health Services Research, Faculty of Medicine and University Hospital, University of Cologne, Germany