1. Department of Medical Statistics, London School of Hygiene and Tropical Medicine University of London London UK
2. Women and Children First London UK
3. ESORT Studies London UK
4. Patient and Public Involvement (PPI) London UK
5. Department of Health Services Research and Policy London School of Hygiene and Tropical Medicine London UK
6. Department of Surgery Royal Alexandra Hospital Paisley Renfrewshire UK
7. Trent Oesophago‐Gastric Unit, Nottingham University Hospitals NHS Trust City Hospital Campus Nottingham UK
8. Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust Queen's Medical Centre Nottingham UK