1 ENT Department, University College Hospital, London, UK.
2 ENT Department, Evelina London Children's Hospital, London, UK.
3 ENT Department, Charing Cross Hospital, Imperial College NHS Trust, London, UK.
4 ENT Department, Glasgow Royal Infirmary and Queen Elizabeth University Hospital, Glasgow, UK.
5 ENT Department, Addenbrooke's Hospital, Cambridge, UK.
6 Department of Surgery - Otolaryngology Head and Neck Surgery, Adelaide Universities, The Queen Elizabeth Hospital, Woodville, South Australia, Australia.
7 ENT Department, Royal Cornwall Hospital, Truro, UK.
8 University of Exeter Medical School, Royal Cornwall Hospital, Truro, UK.