1. Department of Surgery, University Hospitals, Coventry and Warwickshire NHS Trust, Coventry, UK
2. Clinical Sciences Research Institute, University of Warwick, Coventry, UK
3. Department of Medical Statistics, Warwick Medical School, University of Warwick, Coventry, UK
4. English Colorectal Cancer Screening Pilot, Hospital of St Cross, Rugby (UHCW NHS Trust), Coventry, UK