1. Ear, Nose and Throat Department, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
2. Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
3. Leeds Institute of Clinical Trials Research, University of Leeds, Leeds, UK
4. Newcastle Clinical Trials Unit, Newcastle University, Newcastle upon Tyne, UK
5. Biostatistics Research Group, Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK
6. Ear, Nose and Throat Department, Nottingham University Hospitals NHS Trust, Nottingham, UK
7. Ear, Nose and Throat Department, NHS Greater Glasgow and Clyde, Glasgow, UK
8. Oxford Institute of Nursing, Midwifery and Allied Health Research, Oxford Brookes University, Oxford, UK
9. Ear, Nose and Throat Department, Manchester University NHS Foundation Trust, Manchester, UK
10. Ear, Nose and Throat Department, Brighton and Sussex University Hospitals NHS Trust, Brighton, UK
11. Ear, Nose and Throat Department, City Hospitals Sunderland NHS Foundation Trust, Sunderland, UK
12. Ear, Nose and Throat Department, Stockport NHS Foundation Trust, Stockport, UK
13. Ear, Nose and Throat Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK