1. Queen Alexandra Hospital; Portsmouth; UK
2. Clinical Trial Service Unit; University of Oxford; Oxford; UK
3. Birmingham Clinical Trials Unit; University of Birmingham; Birmingham; UK
4. Sexual Health and HIV Research Department; Whittall Street Clinic; Birmingham; UK
5. Haematology Clinical Trials Unit; Cardiff University School of Medicine; Cardiff; UK
6. Colorectal Surgery Unit; Nottingham University Hospitals; Nottingham; UK
7. Cancer Research UK Clinical Trials Unit; University of Birmingham; Birmingham; UK
8. St Mark's Hospital for Intestinal and Colorectal Disorders; London; UK