title: Effect of protocol-related variables and women's characteristics on the cumulative false-positive risk in breast cancer screening.
abstract: BACKGROUND
  Reducing the false-positive risk in breast cancer screening is important. We examined how the screening-protocol and women's characteristics affect the cumulative false-positive risk.
  
  
  METHODS
  This is a retrospective cohort study of 1,565,364 women aged 45-69 years who underwent 4,739,498 screening mammograms from 1990 to 2006. Multilevel discrete hazard models were used to estimate the cumulative false-positive risk over 10 sequential mammograms under different risk scenarios.
  
  
  RESULTS
  The factors affecting the false-positive risk for any procedure and for invasive procedures were double mammogram reading [odds ratio (OR)=2.06 and 4.44, respectively], two mammographic views (OR=0.77 and 1.56, respectively), digital mammography (OR=0.83 for invasive procedures), premenopausal status (OR=1.31 and 1.22, respectively), use of hormone replacement therapy (OR=1.03 and 0.84, respectively), previous invasive procedures (OR=1.52 and 2.00, respectively), and a familial history of breast cancer (OR=1.18 and 1.21, respectively). The cumulative false-positive risk for women who started screening at age 50-51 was 20.39% [95% confidence interval (CI) 20.02-20.76], ranging from 51.43% to 7.47% in the highest and lowest risk profiles, respectively. The cumulative risk for invasive procedures was 1.76% (95% CI 1.66-1.87), ranging from 12.02% to 1.58%.
  
  
  CONCLUSIONS
  The cumulative false-positive risk varied widely depending on the factors studied. These findings are relevant to provide women with accurate information and to improve the effectiveness of screening programs.
authors: Department of Epidemiology and Evaluation, Institut Municipal d'Investigació Mèdica-Parc de Salut Mar Barcelona; CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona.
authors: R
authors: R
authors: Román
authors: Department of Epidemiology and Evaluation, Institut Municipal d'Investigació Mèdica-Parc de Salut Mar Barcelona; CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona.
authors: M
authors: M
authors: Sala
authors: General Directorate of Public Health and Centre for Public Health Research, Valencia.
authors: D
authors: D
authors: Salas
authors: CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona; Navarra Breast Cancer Screening Programme, Public Health Institute, CIBERESP, Pamplona.
authors: N
authors: N
authors: Ascunce
authors: Galician Breast Cancer Screening Programme, Public Health and Planning Directorate, Health Office, Santiago de Compostela.
authors: R
authors: R
authors: Zubizarreta
authors: Department of Epidemiology and Evaluation, Institut Municipal d'Investigació Mèdica-Parc de Salut Mar Barcelona; CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona; Department of Pediatrics, Obstetrics and Gynecology, Preventive Medicine and Public Health, Universitat Autònoma de Barcelona (UAB), Bellaterra (Barcelona), Spain. Electronic address: xcastells@parcdesalutmar.cat.
authors: X
authors: X
authors: Castells
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000706:statistics & numerical data*; D008403:Mass Screening / Q000379:methods* / Q000706:statistics & numerical data*; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors