[1] NHS Screening Programmes, Publ Hlth, Bristol, Avon, England
[2] Univ Bristol, Sch Community & Social Med, Canynge Hall,58 Whiteladies Rd, Bristol BS8 2PL, Avon, England
[3] UK Natl Screening Comm 1996 2007, Oxford, England
[4] Oxford Ctr Triple Value Healthcare, Oxford, England