UCSF

Objective

The purpose of this study was to determine whether digital breast tomosynthesis (DBT) adoption was associated with a decrease in screening mammography capacity across Breast Cancer Screening Consortium facilities, given concerns about increasing imaging and interpretation times associated with DBT.

Subjects and methods

Facility characteristics and examination volume data were collected prospectively from Breast Cancer Screening Consortium facilities that adopted DBT between 2011 and 2014. Interrupted time series analyses using Poisson regression models in which facility was considered a random effect were used to evaluate differences between monthly screening volumes during the 12-month preadoption period and the 12-month postadoption period (with the two periods separated by a 3-month lag) and to test for changes in month-to-month facility-level screening volume during the preadoption and postadoption periods.

Results

Across five regional breast imaging registries, 15 of 83 facilities (18.1%) adopted DBT for screening between 2011 and 2014. Most had no academic affiliation (73.3% [11/15]), were nonprofit (80.0% [12/15]), and were general radiology practices (66.7% [10/15]). Facility-level monthly screening volumes were slightly higher during the postadoption versus preadoption periods (relative risk [RR], 1.09; 95% CI, 1.06-1.11). Monthly screening volumes remained relatively stable within the preadoption period (RR, 1.00 per month; 95% CI 1.00-1.01 per month) and the postadoption period (RR, 1.00; 95% CI, 1.00-1.01 per month).

Conclusion

In a cohort of facilities with varied characteristics, monthly screening examination volumes did not decrease after DBT adoption.