1. Department of Otolaryngology, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich
2. Department of Otolaryngology, Guy's and St Thomas' NHS Foundation Trust, London
3. Norwich Medical School, University of East Anglia, Norwich, England
4. Department of Otolaryngology, University Hospitals of Leicester NHS Trust, Leicester, Leicestershire
5. Department of Otolaryngology, Imperial College Healthcare NHS Trust, London, England, UK