Effects of digital mammography uptake on downstream breast-related care among older women.

BACKGROUND: Digital mammography is the dominant modality for breast cancer screening in the United States. No previous studies have investigated as to how introducing digital mammography affects downstream breast-related care.
OBJECTIVE: Compare breast-related health care use after a screening mammogram before and after introduction of digital mammography. RESEARCH DESIGN AND
SUBJECTS: Longitudinal study of screening mammograms from 14 radiology facilities contributing data to the Breast Cancer Surveillance Consortium performed 1 year before and 4 years after each facility introduced digital mammography, along with linked Medicare claims. We included 30,211 mammograms for women aged 66 years and older without breast cancer. MEASURES: Rates of false-positive recall and short-interval follow-up were based on radiologists' assessments and recommendations; rates of follow-up mammography, ultrasound, and breast biopsy use were based on Medicare claims.
RESULTS: False-positive recall rates increased after the introduction of digital mammography. Follow-up mammography use was significantly higher across all 4 years after a facility began using digital mammography compared with the year before [year 1 odds ratio (OR) = 1.7, 95% confidence interval (CI), 1.4-2.1]. Among women with false-positive mammography results, use of ultrasound decreased significantly in the second through fourth years after digital mammography began (year 2 OR = 0.4, 95% CI, 0.3-0.6).
CONCLUSIONS: Introduction of a new technology led to changes in health care use that persisted for at least 4 years. Comparative effectiveness research on new technologies should consider not only diagnostic performance but also downstream utilization attributable to this apparent learning curve.