1. VITIS Healthcare Group, Cologne, Germany.
2. KCM KompetenzCentrum für Medizinoekonomie, FOM University of Applied Sciences, Essen, Germany.
3. Department of Orthopedics and Trauma Surgery, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany.
4. Department I of Internal Medicine, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
5. Faculty of Medicine and University Hospital Cologne, Centre for Integrated Oncology (CIO ABCD), University of Cologne, Cologne, Germany.