1. Misclassification of Breast Imaging Reporting and Data System ( BI- RADS) Mammographic Density and Implications for Breast Density Reporting Legislation.
- Author
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Gard, Charlotte C., Aiello Bowles, Erin J., Miglioretti, Diana L., Taplin, Stephen H., and Rutter, Carolyn M.
- Subjects
BREAST tumors ,MAMMOGRAMS ,CONFIDENCE intervals ,DIAGNOSTIC imaging ,COMPUTERS in medicine ,RADIOLOGISTS ,RESEARCH funding ,STATISTICAL sampling ,STATISTICS ,DATA analysis software ,MEDICAL laws - Abstract
USA states have begun legislating mammographic breast density reporting to women, requiring that women undergoing screening mammography who have dense breast tissue (Breast Imaging Reporting and Data System [ BI- RADS] density c or d) receive written notification of their breast density; however, the impact that misclassification of breast density will have on this reporting remains unclear. The aim of this study was to assess reproducibility of the four-category BI- RADS density measure and examine its relationship with a continuous measure of percent density. We enrolled 19 radiologists, experienced in breast imaging, from a single integrated health care system. Radiologists interpreted 341 screening mammograms at two points in time 6 months apart. We assessed intra- and interobserver agreement in radiologists'; interpretations of BI- RADS density and explored whether agreement depended upon radiologist characteristics. We examined the relationship between BI- RADS density and percent density in a subset of 282 examinations. Intraradiologist agreement was moderate to substantial, with kappa varying across radiologists from 0.50 to 0.81 (mean = 0.69, 95% CI [0.63, 0.73]). Intraradiologist agreement was higher for radiologists with ≥10 years experience interpreting mammograms (difference in mean kappa = 0.10, 95% CI [0.01, 0.24]). Interradiologist agreement varied widely across radiologist pairs from slight to substantial, with kappa ranging from 0.02 to 0.72 (mean = 0.46, 95% CI [0.36, 0.55]). Of 145 examinations interpreted as 'nondense' ( BI- RADS density a or b) by the majority of radiologists, 82.8% were interpreted as 'dense' ( BI- RADS density c or d) by at least one radiologist. Of 187 examinations interpreted as 'dense' by the majority of radiologists, 47.1% were interpreted as 'nondense' by at least one radiologist. While the examinations of almost half of the women in our study were interpreted clinically as having BI- RADS density c or d, only about 10% of examinations had percent density >50%. Our results suggest that breast density reporting based on a single BI- RADS density interpretation may be misleading due to high interradiologist variability and a lack of correspondence between BI- RADS density and percent density. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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