1. Institute for Health Services Research in Dermatology and Nursing (IVPD); German Center for Health Sevices Research in Dermatology (CVderm), University Medical Center Hamburg-Eppendorf; Hamburg Germany
2. Center for Psoriasis, Department of Dermatology, Venereology, and Allergology; University Hospital Schleswig- Holstein; Campus Kiel Kiel Germany
3. Institute and Outpatient Clinic for Medical Psychology; University Medical Center Hamburg-Eppendorf; Hamburg Germany
4. Dermatological Practice; Selters Germany
5. Division of Evidence-based Medicine (dEBM); Department of Dermatology, Venereology, and Allergology at the Charité - Medical Faculty of the University of Berlin; Berlin Germany
6. Dermatologikum Hamburg; Hamburg Germany
7. Dermatological Practice Mönchengladbach; Mönchengladbach Germany
8. Department of Dermatology and Venereology; University Hospital Halle; Halle Germany