1. University Medical Centre Mainz; Institute of Medical Biostatistics; Epidemiology and Informatics (IMBEI); Mainz Germany
2. University of Leipzig; Division of Psychosocial Oncology; Leipzig Germany
3. University of Leipzig; Department of Psychosomatic Medicine and Psychotherapy; Leipzig Germany
4. Jena University Hospital; Department of Otorhinolaryngology; Jena Germany
5. Hospital Chemnitz; Department of Otorhinolaryngology; Chemnitz Germany
6. Hospital Dresden-Friedrichstadt; Department of Otorhinolaryngology; Dresden Germany
7. Hospital Martha-Maria; Department of Otorhinolaryngology; Halle-Dölau Germany
8. Hospital Elblandkliniken; Department of Otorhinolaryngology; Riesa Germany
9. Community Hospital St. Georg; Department of Otorhinolaryngology; Leipzig Germany
10. University of Leipzig; Department of Otorhinolaryngology; Leipzig Germany