A new study published in the Journal of the National Cancer Institute has found that diagnostic interpretative performance varies across mammography facilities.

Prior work demonstrated that screening mammography interpretive accuracy varies substantially by facility, but performance of diagnostic interpretation (i.e., exams performed to evaluate a clinical breast lump) was unknown. To determine if such variability exits, Sara L. Jackson, M.D., of the University of Washington School of Medicine in Seattle, and colleagues surveyed 45 facilities in the Breast Cancer Surveillance Consortium to compare mammography facility structure, organization, and interpretive processes. Analyzing data from over 28,000 diagnostic mammograms read by 118 radiologists, they assessed whether facility characteristics were associated with facility interpretive performance of diagnostic mammograms.

After adjustment for patient and radiologist characteristics, researchers found statistically significant variability for false-positive rates between facilities. False positive rates were higher at facilities reporting increased concern about malpractice.

"Analyses comparing differences among mammography facilities that do not adjust for important patient characteristics may falsely conclude that there is more facility variation in overall accuracy than what actually exists," the authors write.

SOURCE:
Journal of the National Cancer Institute, May 26, 2009