title: Discrepant screening mammography assessments at blinded and non-blinded double reading: impact of arbitration by a third reader on screening outcome.
abstract: OBJECTIVE
  To determine the value of adding a third reader for arbitration of discrepant screening mammography assessments.
  
  
  METHODS
  We included a consecutive series of 84,927 digital screening mammograms, double read in a blinded or non-blinded fashion. Arbitration was retrospectively performed by a third screening radiologist. Two years' follow-up was performed.
  
  
  RESULTS
  Discrepant readings comprised 57.2% (830/1452) and 29.1% (346/1188) of recalls at blinded and non-blinded double readings, respectively. At blinded double reading, arbitration would have decreased recall rate (3.4 to 2.2%, p < 0.001) and programme sensitivity (83.2 to 76.0%, p = 0.013), would not have influenced the cancer detection rate (CDR; 7.5 to 6.8 per 1,000 screens, p = 0.258) and would have increased the positive predictive value of recall (PPV; 22.3 to 31.2%, p < 0.001). At non-blinded double reading, arbitration would have decreased recall rate (2.8 to 2.3%, p < 0.001) and increased PPV (23.2 to 27.5%, p = 0.021), but would not have affected CDR (6.6 to 6.3 per 1,000 screens, p = 0.604) and programme sensitivity (76.0 to 72.7%, p = 0.308).
  
  
  CONCLUSIONS
  Arbitration of discrepant screening mammography assessments is a good tool to improve recall rate and PPV, but is not desirable as it reduces the programme sensitivity at blinded double reading.
  
  
  CONCLUSIONS
  • Blinded double reading results in higher programme sensitivity than non-blinded reading. • Discrepant readings occur more often at blinded compared to non-blinded reading. • Arbitration of discrepant readings reduces the recall rate and PPV. • Arbitration would reduce the programme sensitivity at blinded double reading.
authors.affiliation: Department of Radiology, Catharina Hospital, PO Box 1350, 5602 ZA, Eindhoven, The Netherlands, elisabethgenevieve@hotmail.com.
authors.forename: Elisabeth G
authors.initials: EG
authors.lastname: Klompenhouwer
authors.forename: Adri C
authors.initials: AC
authors.lastname: Voogd
authors.forename: Gerard J
authors.initials: GJ
authors.lastname: den Heeten
authors.forename: Luc J A
authors.initials: LJ
authors.lastname: Strobbe
authors.forename: Vivianne C
authors.initials: VC
authors.lastname: Tjan-Heijnen
authors.forename: Mireille J M
authors.initials: MJ
authors.lastname: Broeders
authors.forename: Lucien E M
authors.initials: LE
authors.lastname: Duijm
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D057210:Delayed Diagnosis; D004311:Double-Blind Method; D055088:Early Detection of Cancer / Q000379:methods / Q000592:standards; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods* / Q000592:standards; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D017008:Negotiating; D015588:Observer Variation; D012189:Retrospective Studies