Affiliation: | 1. Department of Surgery, Yeovil District Hospital NHS Foundation Trust, Yeovil, UK;2. Academic Unit of Surgical Research, School of Social and Community Medicine, University of Bristol, UK;3. South West Research Design Service, Musgrove Park Hospital, Taunton, UK;4. Department of Surgery, St Mark's Hospital, Northwick Park, Harrow, UK;5. University Hospitals Bristol NHS Foundation Trust, Bristol, UK |