title: Variation in false-positive rates of mammography reading among 1067 radiologists: a population-based assessment.
abstract: BACKGROUND
  The accuracy of mammography reading varies among radiologists. We conducted a population-based assessment on radiologist variation in false- positive rates of screening mammography and its associated radiologist characteristics.
  
  
  METHODS
  About 27,394 screening mammograms interpreted by 1067 radiologists were identified from a 5% non-cancer sample of Medicare claims during 1998-1999. The data were linked to the American Medical Association Masterfile to obtain radiologist characteristics. Multilevel logistic regression models were used to examine the radiologist variation in false-positive rates of screening mammography and the associated radiologist characteristics.
  
  
  RESULTS
  Radiologists varied substantially in the false-positive rates of screening mammography (ranging from 1.5 to 24.1%, adjusting for patient characteristics). A longer time period since graduation is associated with lower false-positive rates (odds ratio [OR] for every 10 years increase: 0.87, 95% Confidence Interval [CI], 0.81-0.94) and female radiologists had higher false-positive rates than male radiologists (OR = 1.25, 95% CI, 1.05-1.49), adjusting for patient and other radiologist characteristics. The unmeasured factors contributed to about 90% of the between-radiologist variance.
  
  
  CONCLUSIONS
  Radiologists varied greatly in accuracy of mammography reading. Female and more recently trained radiologists had higher false-positive rates. The variation among radiologists was largely due to unmeasured factors, especially unmeasured radiologist factors. If our results are confirmed in further studies, they suggest that system-level interventions would be required to reduce variation in mammography interpretation.
authors.affiliation: Department of Preventive Medicine and Community Health, Office of Epidemiology and Biostatistics, University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas 77555-1148, USA. altan@utmb.edu
authors.forename: Alai
authors.initials: A
authors.lastname: Tan
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Freeman
authors.forename: James S
authors.initials: JS
authors.lastname: Goodwin
authors.forename: Jean L
authors.initials: JL
authors.lastname: Freeman
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000208:ethnology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008327:Mammography / Q000592:standards*; D006278:Medicare; D008875:Middle Aged; D015588:Observer Variation; D016017:Odds Ratio; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011871:Radiology / Q000592:standards*; D015203:Reproducibility of Results; D012111:Residence Characteristics; D018426:SEER Program; D012737:Sex Factors; D013997:Time Factors; D014481:United States