[1] Univ Bristol, Surg Res Ctr, Sch Social & Community Med, Bristol BS8 2PS, Avon, England
[2] Univ Hosp Bristol NHS Fdn Trust, Severn Sch Surg, Bristol, Avon, England
[3] Univ Hosp Bristol NHS Fdn Trust, Div Surg Head & Neck, Bristol, Avon, England
[4] North Bristol NHS Trust, Bristol, Avon, England
[5] North Bristol NHS Trust, Dept Gen Surg, Bristol, Avon, England
[6] Univ Hosp Bristol NHS Fdn Trust, Colorectal Surg Unit, Bristol, Avon, England
[7] Natl Inst Canc Res, Colorectal Consumer Liaison Grp, London, England
[8] Univ Birmingham, Acad Dept Surg, Birmingham, W Midlands, England
[9] St Marks Hosp & Acad Inst, Dept Surg, Harrow, Middx, England
[10] St James Univ Hosp, Acad Surg Unit, Leeds, W Yorkshire, England
[11] Univ Bristol, Ctr Eth Med, Bristol, Avon, England
[12] Avon Somerset & Wiltshire Canc Serv, Colorectal Network Site Specif Grp, Bristol, Avon, England
[13] Univ Oxford, Ctr Stat Med, Oxford, England
[14] Univ Oxford, Oxford Clin Trials Res Unit, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford, England
[15] Plymouth Hosp NHS Trust, Dept Colorectal Surg, Plymouth, Devon, England
[16] Univ Leeds, Clin Trials Res Unit, Leeds, W Yorkshire, England