title: Design and preliminary recruitment results of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP).
abstract: BACKGROUND
  Screening for prostate cancer continues to generate controversy because of concerns about over-diagnosis and unnecessary treatment. We describe the rationale, design and recruitment of the Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial, a UK-wide cluster randomised controlled trial investigating the effectiveness and cost-effectiveness of prostate-specific antigen (PSA) testing.
  
  
  METHODS
  Seven hundred and eighty-five general practitioner (GP) practices in England and Wales were randomised to a population-based PSA testing or standard care and then approached for consent to participate. In the intervention arm, men aged 50-69 years were invited to undergo PSA testing, and those diagnosed with localised prostate cancer were invited into a treatment trial. Control arm practices undertook standard UK management. All men were flagged with the Health and Social Care Information Centre for deaths and cancer registrations. The primary outcome is prostate cancer mortality at a median 10-year-follow-up.
  
  
  RESULTS
  Among randomised practices, 271 (68%) in the intervention arm (198,114 men) and 302 (78%) in the control arm (221,929 men) consented to participate, meeting pre-specified power requirements. There was little evidence of differences between trial arms in measured baseline characteristics of the consenting GP practices (or men within those practices).
  
  
  CONCLUSIONS
  The CAP trial successfully met its recruitment targets and will make an important contribution to international understanding of PSA-based prostate cancer screening.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: E L
authors.initials: EL
authors.lastname: Turner
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: C
authors.initials: C
authors.lastname: Metcalfe
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: J L
authors.initials: JL
authors.lastname: Donovan
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: S
authors.initials: S
authors.lastname: Noble
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: J A C
authors.initials: JA
authors.lastname: Sterne
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: J A
authors.initials: JA
authors.lastname: Lane
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: K N
authors.initials: KN
authors.lastname: Avery
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: L
authors.initials: L
authors.lastname: Down
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: E
authors.initials: E
authors.lastname: Walsh
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: M
authors.initials: M
authors.lastname: Davis
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Ben-Shlomo
authors.affiliation: Department of Health Sciences, University of York and the Hull York Medical School, York YO10 5DD, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Oliver
authors.affiliation: Royal United Hospital Bath, Combe Park, Bath BA1 3NG, UK.
authors.forename: S
authors.initials: S
authors.lastname: Evans
authors.affiliation: Avon Primary Care Research Collaborative, Marlborough Street, South Plaza, Bristol BS1 3NX, UK.
authors.forename: P
authors.initials: P
authors.lastname: Brindle
authors.affiliation: School of Social and Community Medicine, University of Bristol, Royal Hallamshire Hospital, Sheffield S10 2JF, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: Williams
authors.affiliation: Department of Oncology, University of Cambridge, Box 279 (S4), Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
authors.forename: L J
authors.initials: LJ
authors.lastname: Hughes
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: E M
authors.initials: EM
authors.lastname: Hill
authors.affiliation: School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK.
authors.forename: C
authors.initials: C
authors.lastname: Davies
authors.affiliation: School of Social and Community Medicine, University of Bristol, Freeman Hospital, High Heaton, Newcastle upon Tyne NE7 7DN, UK.
authors.forename: S Y
authors.initials: SY
authors.lastname: Ng
authors.affiliation: Department of Oncology, University of Cambridge, Box 279 (S4), Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
authors.forename: D E
authors.initials: DE
authors.lastname: Neal
authors.affiliation: Nuffield Department of Surgical Sciences, John Radcliffe Hospital, Oxford OX3 9DU, UK.
authors.forename: F C
authors.initials: FC
authors.lastname: Hamdy
authors.affiliation: 1] School of Social and Community Medicine, University of Bristol, Canynge Hall, 39 Whatley Road, Bristol BS8 2PS, UK [2] MRC/University of Bristol Integrative Epidemiology Unit, University of Bristol, Oakfield House, Oakfield Grove, Bristol BS8 2BN, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: Martin
mesh_terms: D000368:Aged; D003362:Cost-Benefit Analysis; D055088:Early Detection of Cancer / Q000191:economics* / Q000379:methods*; D004739:England; D058005:General Practitioners; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods; D008875:Middle Aged; D018579:Patient Selection; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000401:mortality; D012107:Research Design; D014852:Wales
chemical_list: D017430:Prostate-Specific Antigen