title: Predictors of repeat participation in the NHS bowel cancer screening programme.
abstract: OBJECTIVE
  Most types of population-based cancer screening require repeat participation to be effective. This study investigated predictors of repeat participation in the NHS Bowel Cancer Screening Programme (BCSP).
  
  
  METHODS
  The BCSP in England offers biennial colorectal cancer screening using a guaiac fecal occult blood test (gFOBt) from age 60-74 years. This analysis included 62,081 individuals aged 60-64 years at the time of the first invitation (R1). The main outcome was repeat participation at their second (R2) or third (R3) invitation. Behavioural measures derived from screening records included late return of the gFOBt kit, compliance with follow-up investigations and previous screening participation. Other potential predictors of repeat participation included results of individual test kit analysis (normal, weak positive, strong positive, spoilt) and the definitive result of the gFOBt screening episode (normal or abnormal). Age, sex and socioeconomic deprivation were also recorded.
  
  
  RESULTS
  Overall repeat uptake was 86.6% in R2 and 88.6% in R3. Late return of the test kit was consistently associated with lower uptake (R2: 82.3% vs 88.6%, P<0.001; R3: 84.5% vs 90.5%, P<0.001). A definitive abnormal gFOBt result in the previous screening episode was a negative predictor of repeat uptake (R2: 61.4% vs 86.8%, P<0.001; R3: 65.7% vs 88.8%, P<0.001). Weak positive (R2: 76.9% vs 86.8%, P<0.001; R3: 81.7% vs 88.8%, P<0.05) and spoilt test kits (R2: 79.0% vs 86.6%, NS; R3: 84.2% vs 92.2%, P<0.05) were associated with lower repeat uptake, but were not consistently independent predictors in all invitation rounds or subgroups. Among those with a definitive abnormal gFOBt result, noncompliance with follow-up in a previous screening episode was also associated with lower repeat uptake (R2: 24.3% vs 67.1%, P<0.001; R3: 43.2% vs 69.9%, P<0.001).
  
  
  CONCLUSIONS
  Behavioural markers and test results from previous screening episodes have been implicated in subsequent gFOBt uptake.
authors.affiliation: Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London WC1E 6BT , UK.
authors.forename: S H
authors.initials: SH
authors.lastname: Lo
authors.affiliation: 1] Bowel Cancer Screening Southern Programme Hub, Royal Surrey County Hospital NHS Trust, Surrey Research Park, Guildford, Surrey, UK [2] Department of Biochemistry and Physiology, University of Surrey, Guildford, Surrey, UK [3] Guildford Undetected Tumour Screening (GUTS) Charity, Royal Surrey County Hospital NHS Trust, Guildford, Surrey, UK.
authors.forename: S
authors.initials: S
authors.lastname: Halloran
authors.affiliation: Bowel Cancer Screening Southern Programme Hub, Royal Surrey County Hospital NHS Trust, Surrey Research Park, Guildford, Surrey, UK.
authors.forename: J
authors.initials: J
authors.lastname: Snowball
authors.affiliation: 1] Bowel Cancer Screening Southern Programme Hub, Royal Surrey County Hospital NHS Trust, Surrey Research Park, Guildford, Surrey, UK [2] Department of Biochemistry and Physiology, University of Surrey, Guildford, Surrey, UK [3] Guildford Undetected Tumour Screening (GUTS) Charity, Royal Surrey County Hospital NHS Trust, Guildford, Surrey, UK.
authors.forename: H
authors.initials: H
authors.lastname: Seaman
authors.affiliation: Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London WC1E 6BT , UK.
authors.forename: J
authors.initials: J
authors.lastname: Wardle
authors.affiliation: Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London WC1E 6BT , UK.
authors.forename: C
authors.initials: C
authors.lastname: von Wagner
mesh_terms: D000368:Aged; D003113:Colonoscopy / Q000379:methods* / Q000523:psychology / Q000706:statistics & numerical data; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D055088:Early Detection of Cancer / Q000379:methods* / Q000523:psychology; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged