[1] London Sch Hyg & Trop Med, Dept Hlth Serv Res & Policy, 15-17 Tavistock Pl, London WC1H 9SH, England
[2] Royal Coll Surgeons England, Clin Effectiveness Unit, London, England
[3] Christie NHS Fdn Trust, Dept Oncol, Manchester, England
[4] Univ Manchester, Sch Med Sci, Manchester, England
[5] Cambridge Univ Hosp, Dept Colorectal Surg, Cambridge, England
[6] Kings Coll London, Inst Canc Policy, London, England
[7] Guys & St Thomas NHS Trust, Dept Oncol, London, England