title: Breast MRI BI-RADS assessments and abnormal interpretation rates by clinical indication in US community practices.
abstract: OBJECTIVE
  As breast magnetic resonance imaging (MRI) use grows, benchmark performance parameters are needed for auditing and quality assurance purposes. We describe the variation in breast MRI abnormal interpretation rates (AIRs) by clinical indication among a large sample of US community practices.
  
  
  METHODS
  We analyzed data from 41 facilities across five Breast Cancer Surveillance Consortium imaging registries. Each registry obtained institutional review board approval for this Health Insurance Portability and Accountability Act compliant analysis. We included 11,654 breast MRI examinations conducted in 2005-2010 among women aged 18-79 years. We categorized clinical indications as 1) screening, 2) extent of disease, 3) diagnostic (eg, breast symptoms), and 4) other (eg, short-interval follow-up). We characterized assessments as positive (ie, Breast Imaging Reporting and Data System [BI-RADS] 0, 4, and 5) or negative (ie, BI-RADS 1, 2, and 6) and provide results with BI-RADS 3 categorized as positive and negative. We tested for differences in AIRs across clinical indications both unadjusted and adjusted for patient characteristics and registry and assessed for changes in AIRs by year within each clinical indication.
  
  
  RESULTS
  When categorizing BI-RADS 3 as positive, AIRs were 21.0% (95% confidence interval [CI], 19.8-22.3) for screening, 31.7% (95% CI, 29.6-33.8) for extent of disease, 29.7% (95% CI, 28.3-31.1) for diagnostic, and 27.4% (95% CI, 25.0-29.8) for other indications (P < .0001). When categorizing BI-RADS 3 as negative, AIRs were 10.5% (95% CI, 9.5-11.4) for screening, 21.8% (95% CI, 19.9-23.6) for extent of disease, 17.7% (95% CI, 16.5-18.8) for diagnostic, and 13.3% (95% CI, 11.6-15.2) for other indications (P < .0001). The significant differences in AIRs by indication persisted even after adjusting for patient characteristics and registry (P < .0001). In addition, for most indications, there were no significant changes in AIRs over time.
  
  
  CONCLUSIONS
  Breast MRI AIRs differ significantly by clinical indication. Practices should stratify breast MRI examinations by indication for quality assurance and auditing purposes.
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 825 Eastlake Ave East, G3-200, Seattle, WA, 98109-1023; Department of Health Services, University of Washington School of Public Health, Seattle, Washington. Electronic address: stophlee@uw.edu.
authors.forename: Christoph I
authors.initials: CI
authors.lastname: Lee
authors.affiliation: Group Health Research Institute, Seattle, Washington.
authors.forename: Laura
authors.initials: L
authors.lastname: Ichikawa
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 825 Eastlake Ave East, G3-200, Seattle, WA, 98109-1023.
authors.forename: Michele C
authors.initials: MC
authors.lastname: Rochelle
authors.affiliation: General Internal Medicine Section, Department of Veterans Affairs, University of California, San Francisco, San Francisco, California; Department of Medicine, University of California, San Francisco, San Francisco, California; Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California.
authors.forename: Karla
authors.initials: K
authors.lastname: Kerlikowske
authors.affiliation: Group Health Research Institute, Seattle, Washington; Department of Public Health Sciences, University of California, Davis, Davis, California.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Miglioretti
authors.affiliation: Department of Surgery and Office of Health Promotion Research, University of Vermont, Burlington, Vermont.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Sprague
authors.affiliation: Department of Radiology, University of Wisconsin School of Medicine, Madison, Wisconsin.
authors.forename: Wendy B
authors.initials: WB
authors.lastname: DeMartini
authors.affiliation: Group Health Research Institute, Seattle, Washington.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Wernli
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California.
authors.forename: Bonnie N
authors.initials: BN
authors.lastname: Joe
authors.affiliation: Department of Radiology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina; Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, North Carolina.
authors.forename: Bonnie C
authors.initials: BC
authors.lastname: Yankaskas
authors.affiliation: Department of Radiology, University of Washington School of Medicine, 825 Eastlake Ave East, G3-200, Seattle, WA, 98109-1023.
authors.forename: Constance D
authors.initials: CD
authors.lastname: Lehman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000592:standards* / Q000706:statistics & numerical data*; D008297:Male; D008327:Mammography / Q000592:standards* / Q000706:statistics & numerical data*; D008495:Medical Oncology / Q000592:standards; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000592:standards / Q000706:statistics & numerical data; D015995:Prevalence; D011871:Radiology / Q000592:standards; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Breast magnetic resonance imaging; audit; quality assurance