1. Department of General Surgery Royal Devon Healthcare Trust Barnstaple UK
2. Department of Surgery Sheffield Teaching Hospitals Sheffield UK
3. Kleijnen Systematic Reviews Ltd York UK
4. Royal Derby Hospital, The University of Nottingham Nottingham UK
5. Department of Surgery Royal Derby Hospital Derby UK
6. University Hospital Southampton UK
7. Department of Colorectal Surgery Chelsea and Westminster Hospital NHS Foundation Trust London UK
8. Department of Cancer and Surgery Imperial College London London UK
9. Department of Colorectal Surgery Churchill Hospital Oxford UK
10. Pharmacy Department Royal Devon Healthcare Trust Southampton UK
11. Department of Paediatric Surgery University Hospital Southampton UK
12. St Mark's Hospital, London North West University Healthcare Trust Harrow UK
13. UCL Research Department of Primary Care and Population Health University College London Medical School (Royal Free Hospital Campus) London UK
14. St Mark's Hospital Harrow UK