Comparison of Resource Utilization and Clinical Outcomes Following Screening with Digital Breast Tomosynthesis Versus Digital Mammography: Findings From a Learning Health System

Abstract

To compare outcomes associated with breast cancer screening with digital mammography (DM) alone versus in combination with digital breast tomosynthesis (DBT) in a large representative cohort. A total of 325,729 screening mammograms from 247,431 women were analyzed, across two healthcare systems, from June 2015 to September 2017. Patient level demographic, calculated risk levels, and clinical outcomes were extracted from radiology information system and electronic medical records. Multivariable regression modeling adjusting for institution, age, breast density, and first exam was conducted to compare patient characteristics, recall rates, time to biopsy and final diagnosis, clinical outcomes, and diagnostic performance. Participating institutions and the Coordinating Center received Institutional Review Board approval for a waiver of consent to collect and link data and perform analysis. A total of 194,437 (59.7%) screens were DBT versus 131,292 (40.3%) with DM. Women with dense breasts and higher calculated risk were more likely to be screened with DBT. Recall rates were lower for DBT overall (8.83% DBT vs 10.98% DM, adjusted odds ratio, 95% confidence interval = 0.85, 0.83-0.87) and across all age groups, races, and breast densities, and at facilities that used predominantly DBT (8.05%) versus predominantly DM (11.22%), or a combination (10.73%). The most common diagnostic pathway after recall was mammography and ultrasound. Women recalled from DBT were more likely to proceed directly to ultrasound. The median time to biopsy (18 vs 22 days) and final diagnosis (10 vs 13 days) was shorter for DBT. The adjusted cancer rate, cancer detection rate, and specificity were higher for DBT. DBT demonstrated a more efficient screening pathway and improved quality measures with lower recall rates in all patient types, reduced diagnostic mammography and shorter time to biopsy and final diagnosis.