1. Department of Otorhinolaryngology; Aleris Sabbatsberg; Stockholm Sweden
2. Division of Clinical Science, Intervention and Technology; Karolinska Institutet; Stockholm Sweden
3. Department of Otorhinolaryngology; Sahlgrenska University Hospital; Gothenburg Sweden
4. Institute of Clinical Sciences; Sahlgrenska Academy at the University of Gothenburg; Gothenburg Sweden
5. School of Health and Medical Sciences; Örebro University; Örebro Sweden
6. Sollentuna Specialist Clinic; Stockholm Sweden
7. Department of Otorhinolaryngology; Department of Clinical and Experimental Medicine; Linköping University; Linköping Sweden
8. Department of Otorhinolaryngology; Ryhov County Hospital and Futurum; the Academy for Health and Care; County Council; Jönköping Sweden