title: Effect of radiologist experience on the risk of false-positive results in breast cancer screening programs.
abstract: OBJECTIVE
  To evaluate the effect of radiologist experience on the risk of false-positive results in population-based breast cancer screening programmes.
  
  
  METHODS
  We evaluated 1,440,384 single-read screening mammograms, corresponding to 471,112 women aged 45-69 years participating in four Spanish programmes between 1990 and 2006. The mammograms were interpreted by 72 radiologists.
  
  
  RESULTS
  The overall percentage of false-positive results was 5.85% and that for false-positives resulting in an invasive procedure was 0.38%. Both the risk of false-positives overall and of false-positives leading to an invasive procedure significantly decreased (p < 0.001) with greater reading volume in the previous year: OR 0.77 and OR 0.78, respectively, for a reading volume 500-1,999 mammograms and OR 0.59 and OR 0.60 for a reading volume of >14,999 mammograms with respect to the reference category (<500). The risk of both categories of false-positives was also significantly reduced (p < 0.001) as radiologists' years of experience increased: OR 0.96 and OR 0.84, respectively, for 1 year's experience and OR 0.72 and OR 0.73, respectively, for more than 4 years' experience with regard to the category of <1 year's experience.
  
  
  CONCLUSIONS
  Radiologist experience is a determining factor in the risk of a false-positive result in breast cancer screening.
authors.affiliation: Galician Breast Cancer Screening Programme, Public health & Planning Directorate, Health Office, Galicia, Spain. raquel.zubizarreta.alberdi@sergas.es
authors.forename: Raquel Zubizarreta
authors.initials: RZ
authors.lastname: Alberdi
authors.forename: Ana B Fernández
authors.initials: AB
authors.lastname: Llanes
authors.forename: Raquel Almazán
authors.initials: RA
authors.lastname: Ortega
authors.forename: Rubén Roman
authors.initials: RR
authors.lastname: Expósito
authors.forename: Jose M Velarde
authors.initials: JM
authors.lastname: Collado
authors.forename: Teresa Queiro
authors.initials: TQ
authors.lastname: Verdes
authors.forename: Carmen Natal
authors.initials: CN
authors.lastname: Ramos
authors.forename: María Ederra
authors.initials: ME
authors.lastname: Sanz
authors.forename: Dolores Salas
authors.initials: DS
authors.lastname: Trejo
authors.forename: Xavier Castells
authors.initials: XC
authors.lastname: Oliveres
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D055088:Early Detection of Cancer; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D011871:Radiology / Q000379:methods*; D015203:Reproducibility of Results; D012306:Risk; D013997:Time Factors