1. Department of Psychosomatic Medicine and Psychotherapy Faculty of Medicine and University Hospital Cologne Cologne Germany
2. Department of Orthopedics and Osteology Dr. Becker Rhein‐Sieg‐Klinik Nümbrecht Germany
3. Institute for Health Economics and Clinical Epidemiology, University of Cologne Faculty of Medicine and University Hospital Cologne Cologne Germany
4. Faculty of Business Management and Social Sciences Osnabrück University of Applied Sciences Osnabrück Germany
5. Institute of Medical Sociology, Health Services Research and Rehabilitation Science University of Cologne Cologne Germany
6. Institute of Medical Statistics and Computational Biology University of Cologne Cologne Germany