title: Effect of Using the Same vs Different Order for Second Readings of Screening Mammograms on Rates of Breast Cancer Detection: A Randomized Clinical Trial.
abstract: OBJECTIVE
  Interpreting screening mammograms is a difficult repetitive task that can result in missed cancers and false-positive recalls. In the United Kingdom, 2 film readers independently evaluate each mammogram to search for signs of cancer and examine digital mammograms in batches. However, a vigilance decrement (reduced detection rate with time on task) has been observed in similar settings.
  
  
  OBJECTIVE
  To determine the effect of changing the order for the second film reader of batches of screening mammograms on rates of breast cancer detection.
  
  
  METHODS
  A multicenter, double-blind, cluster randomized clinical trial conducted at 46 specialized breast screening centers from the National Health Service Breast Screening Program in England for 1 year (all between December 20, 2012, and November 3, 2014). Three hundred sixty readers participated (mean, 7.8 readers per center)-186 radiologists, 143 radiography advanced practitioners, and 31 breast clinicians, all fully qualified to report mammograms in the NHS breast screening program.
  
  
  METHODS
  The 2 readers examined each batch of digital mammograms in the same order in the control group and in the opposite order to one another in the intervention group.
  
  
  METHODS
  The primary outcome was cancer detection rate; secondary outcomes were rates of recall and disagreements between readers.
  
  
  RESULTS
  Among 1,194,147 women (mean age, 59.3; SD, 7.49) who had screening mammograms (596,642 in the intervention group; 597,505 in the control group), the images were interpreted in 37,688 batches (median batch size, 35; interquartile range [IQR]; 16-46), with each reader interpreting a median of 176 batches (IQR, 96-278). After completion of all subsequent diagnostic tests, a total of 10,484 cases (0.88%) of breast cancer were detected. There was no significant difference in cancer detection rate with 5272 cancers (0.88%) detected in the intervention group vs 5212 cancers (0.87%) detected in the control group (difference, 0.01% points; 95% CI, -0.02% to 0.04% points; recall rate, 24,681 [4.14%] vs 24,894 [4.17%]; difference, -0.03% points; 95% CI, -0.10% to 0.04% points; or rate of reader disagreements, 20,471 [3.43%] vs 20,793 [3.48%]; difference, -0.05% points; 95% CI, -0.11% to 0.02% points).
  
  
  CONCLUSIONS
  Interpretation of batches of mammograms by qualified screening mammography readers using a different order vs the same order for the second reading resulted in no significant difference in rates of detection of breast cancer.
  
  
  BACKGROUND
  isrctn.org Identifier: ISRCTN46603370.
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Sian
authors.initials: S
authors.lastname: Taylor-Phillips
authors.affiliation: Cambridge Breast Unit, Cambridge Universities NHS Foundation Trust and NIHR Cambridge Biomedical Research Centre, Cambridge, United Kingdom.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Wallis
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Jenkinson
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Victor
authors.initials: V
authors.lastname: Adekanmbi
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Parsons
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Janet
authors.initials: J
authors.lastname: Dunn
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Nigel
authors.initials: N
authors.lastname: Stallard
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Ala
authors.initials: A
authors.lastname: Szczepura
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Gates
authors.affiliation: Screening QA Service (Midland & East), Seaton House, City Link, Nottingham, United Kingdom.
authors.forename: Olive
authors.initials: O
authors.lastname: Kearins
authors.affiliation: Warwickshire, Solihull and Coventry Breast Screening Service, University Hospitals Coventry and Warwickshire, Coventry, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Duncan
authors.affiliation: Peel & Schriek Consulting Limited, London, United Kingdom.
authors.forename: Sue
authors.initials: S
authors.lastname: Hudson
authors.affiliation: Warwick Medical School, the University of Warwick, Coventry, United Kingdom.
authors.forename: Aileen
authors.initials: A
authors.lastname: Clarke
mesh_terms: D001288:Attention; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D004311:Double-Blind Method; D004739:England; D005260:Female; D006801:Humans; D016015:Logistic Models; D008327:Mammography / Q000706:statistics & numerical data; D008875:Middle Aged; D015588:Observer Variation; D011871:Radiology / Q000706:statistics & numerical data; D018401:Sample Size