title: [Mammography screening in the county of Copenhagen. Results of the first three screening rounds].
abstract: BACKGROUND
  Biennial service mammography screening for breast cancer has been offered to women aged 50-69 years in the municipality of Copenhagen since 1991. We report the results of the first three invitation rounds.
  
  
  METHODS
  Data were collected from the Copenhagen service mammography screening database and other Danish registers.
  
  
  RESULTS
  The average participation rate during the first three invitation rounds was 66%. The breast cancer detection rate was 10/1,000 screened in the first invitation round and 5/1,000 in the consecutive rounds. The probability of a false positive mammography was 6% at the prevalent screen, and this was reduced to 3% at incidence screens. Fifty-two cases of interval cancer were seen after the first invitation round. The expected number was 152, which gives a proportional interval cancer rate of 0.34. The sensitivity was 86% and the specificity 94% after the first round.
  
  
  CONCLUSIONS
  The detection rate of breast cancer was high, especially in the prevalence round. The trend in the incidence of breast cancer at the subsequent rounds was similar to that before screening, which indicates that mammography screening does not lead to any greater over-diagnosis. The rate of false positive mammography was high at the initial screening round, but was acceptable at subsequent rounds, and a false positive mammography does not seem to have affected participation in subsequent rounds. The Copenhagen screening programme conforms to international quality assurance guidelines for process evaluation.
authors.affiliation: Onkologisk Klinik 5073, Finsencentret, H:S Rigshospitalet, DK-2100 København.
authors.forename: Ulla Brix
authors.initials: UB
authors.lastname: Tange
authors.forename: Fred R
authors.initials: FR
authors.lastname: Hirsch
authors.forename: Maj-Britt
authors.initials: MB
authors.lastname: Jensen
authors.forename: Anne Helene
authors.initials: AH
authors.lastname: Olsen
authors.forename: Mogens
authors.initials: M
authors.lastname: Blichert-Toft
authors.forename: Fritz E
authors.initials: FE
authors.lastname: Rank
authors.forename: Ilse M M
authors.initials: IM
authors.lastname: Vejborg
authors.forename: Henning
authors.initials: H
authors.lastname: Mouridsen
authors.forename: Elsebeth
authors.initials: E
authors.lastname: Lynge
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000191:economics / Q000453:epidemiology; D003718:Denmark / Q000453:epidemiology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000592:standards; D008403:Mass Screening; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D011785:Quality Assurance, Health Care; D012680:Sensitivity and Specificity