title: The influence of previous films on screening mammographic interpretation and detection of breast carcinoma.
abstract: OBJECTIVE
  To establish if the availability of previous mammograms improves the detection rate of carcinomas and reduces supplementary examinations in the National Health Service Breast Screening Programme (NHSBSP).
  
  
  METHODS
  Eight radiologists with varying experience but an interest in reporting mammograms reported 100 mammograms on two occasions, at least 1 month apart. In this selection of 100 mammograms we randomly inserted 12 abnormal films, with both benign and malignant changes present. These were chosen retrospectively with histological correlation of the abnormality. On the first occasion only the current films were reviewed, however, on the second occasion previous films were available for comparison. The films were viewed under standard viewing conditions, and the participants were asked to comment if they required further views or would refer the patient for either an ultrasound examination or surgical referral.
  
  
  RESULTS
  Receiver operating curves (ROC) were constructed for the group's overall performance on each of the occasions and there was no difference in the curves. This indicates that the presence of previous films did not improve diagnostic accuracy. The presence of previous films did, however, lead to a significant reduction in the number of additional views and ultrasound examinations that would have been requested. The most significant reductions occurred in the group of normal mammograms.
  
  
  CONCLUSIONS
  The presence of previous mammograms does not lead to an improvement in diagnostic accuracy. However, the presence of previous films led to significant reduction in additional examinations and ultrasound examinations.
authors.affiliation: Department of Breast Screening, Nightingale Centre, Withington Hospital, Didsbury, UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Callaway
authors.forename: C R
authors.initials: CR
authors.lastname: Boggis
authors.forename: S A
authors.initials: SA
authors.lastname: Astley
authors.forename: I
authors.initials: I
authors.lastname: Hutt
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000517:prevention & control; D004739:England; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008403:Mass Screening / Q000379:methods*; D015588:Observer Variation; D012372:ROC Curve; D012017:Referral and Consultation; D016217:Ultrasonography, Mammary