1. Division of Otolaryngology – Head & Neck Surgery Brigham and Women's Hospital Harvard Medical School Boston Massachusetts USA
2. Center for Surgery and Public Health Department of Surgery Brigham and Women's Hospital Boston Massachusetts USA
3. Department of Medicine Harvard Medical School The Division of Allergy and Clinical Immunology Brigham and Women's Hospital, and the Jeff and Penny Vinik Center Boston Massachusetts USA
4. Department of Otolaryngology ‐ Head & Neck Surgery Helsinki University Hospital and University of Helsinki Helsinki Finland