1. Department of Health Economics and Health Services Research; Hamburg Center for Health Economics (HCHE), University Medical Center Hamburg-Eppendorf; Hamburg Germany
2. Department of General Internal Medicine and Psychosomatics; Medical University Hospital Heidelberg; Heidelberg Germany
3. Department of Psychosomatic Medicine and Psychotherapy, Medical Faculty; University of Düsseldorf; Düsseldorf Germany
4. Department of Psychosomatic Medicine and Psychotherapy; LWL-University, Ruhr-University Bochum; Bochum Germany
5. NetUnion; Lausanne Switzerland
6. Department of Medical Informatics, Biometry and Epidemiology; University of Erlangen-Nuremberg; Erlangen Germany
7. Department of Psychosomatic Medicine and Psychotherapy; Hannover Medical School; Hannover Germany
8. Department of Psychosomatic Medicine and Psychotherapy; Medical University Hospital Erlangen, University of Erlangen-Nuremberg; Erlangen Germany
9. Department of Clinical Psychology and Psychotherapy; University of Freiburg; Freiburg Germany
10. Department of Clinical Psychology and Psychotherapy; University of Tübingen; Tübingen Germany
11. Department of Psychosomatic Medicine and Psychotherapy; Medical University Hospital Tübingen; Tübingen Germany
12. Department of Medical Psychology and Medical Sociology; University of Leipzig Medical Center; Leipzig Germany