title: Association between radiologists' experience and accuracy in interpreting screening mammograms.
abstract: BACKGROUND
  Radiologists have been observed to differ, sometimes substantially, both in their interpretations of mammograms and in their recommendations for follow-up. The aim of this study was to determine how factors related to radiologists' experience affect the accuracy of mammogram readings.
  
  
  METHODS
  We selected a random sample of screening mammograms from a population-based breast cancer screening program. The sample was composed of 30 women with histopathologically-confirmed breast cancer and 170 women without breast cancer after a 2-year follow-up (the proportion of cancers was oversampled). These 200 mammograms were read by 21 radiologists routinely interpreting mammograms, with different amount of experience, and by seven readers who did not routinely interpret mammograms. All readers were blinded to the results of the screening. A positive assessment was considered when a BI-RADS III, 0, IV, V was reported (additional evaluation required). Diagnostic accuracy was calculated through sensitivity and specificity.
  
  
  RESULTS
  Average specificity was higher in radiologists routinely interpreting mammograms with regard to radiologists who did not (66% vs 56%; p < .001). Multivariate analysis based on routine readers alone showed that specificity was higher among radiologists who followed-up cases for which they recommended further workup (feedback) (OR 1.37; 95% CI 1.03 to 1.85), those spending less than 25% of the working day on breast radiology (OR 1.49; 95% CI 1.18 to 1.89), and those aged more than 45 years old (OR 1.33; 95% CI 1.12 to 1.59); the variable of average annual volume of mammograms interpreted by radiologists, classified as more or less than 5,000 mammograms per year, was not statistically significant (OR 1.06; 95% CI 0.90 to 1.25).
  
  
  CONCLUSIONS
  Among radiologists who read routinely, volume is not associated with better performance when interpreting screening mammograms, although specificity decreased in radiologists not routinely reading mammograms. Follow-up of cases for which further workup is recommended might reduce variability in mammogram readings and improve the quality of breast cancer screening programs.
authors.affiliation: Evaluation and Clinical Epidemiology Department, Hospital del Mar, Passeig Marítim, 25-29, 08003 Barcelona, Spain. emolins@imas.imim.es
authors.forename: Eduard
authors.initials: E
authors.lastname: Molins
authors.forename: Francesc
authors.initials: F
authors.lastname: Macià
authors.forename: Francesc
authors.initials: F
authors.lastname: Ferrer
authors.forename: Maria-Teresa
authors.initials: MT
authors.lastname: Maristany
authors.forename: Xavier
authors.initials: X
authors.lastname: Castells
mesh_terms: D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D002983:Clinical Competence; D005260:Female; D006801:Humans; D008327:Mammography / Q000592:standards* / Q000706:statistics & numerical data; D011871:Radiology