[1] Royal Surrey Cty Hosp, Surrey Pathol Serv, Clin Biochem, Guildford GU2 7YS, Surrey, England
[2] Scottish Bowel Screening Ctr, Dundee, Scotland
[3] Univ Nottingham Hosp, Eastern Hub Bowel Canc Screening Programme, Nottingham NG7 2UH, England
[4] Northwick Pk Hosp & Clin Res Ctr, Clin Biochem, London, England
[5] Univ Hosp Coventry & Warwickshire NHS Trust Midla, Bowel Canc Screening Programme, Coventry, W Midlands, England
[6] Gateshead Hlth NHS Fdn Trust North Eastern Hub, Bowel Canc Screening Programme, Gateshead, England