PROJECT SUMMARY – Comparative Effectiveness Core While technological advances have improved breast cancer screening and surveillance, breast cancer remains the second leading cause of cancer death for women in the United States with documented racial and ethnic disparities in breast cancer mortality. Evidence on how best to improve care related to breast cancer screening and surveillance with a focus on reducing these disparities is lacking. The Breast Cancer Surveillance Consortium (BCSC) has unique data and an established infrastructure to document breast cancer screening and surveillance practice and performance among women in diverse community settings. Dartmouth College, where the Comparative Effectiveness (CE) Core is based, is a BCSC breast imaging registry site. Dartmouth has extensive resources and expertise in decision-analytic modeling methods and application, including an established collaboration with the NCI-funded Cancer Intervention and Surveillance modeling Network (CISNET). Furthermore, Dartmouth researchers pioneered and remain leaders in the study of cancer screening, risk communication, and overdiagnosis. The CE Core will provide specialized expertise in decision science, simulation modeling, risk communication, and qualitative research to efficiently support the Program’s comparative effectiveness and translational goals. In the next funding cycle, the CE Core will continue to provide comparative modeling services with three CISNET simulation models to translate short-term project results to a longer time horizon. Simulations will address the net benefits, harms, and equity impact of innovative breast cancer screening strategies that target screening at a woman level based on advanced cancer risk and will examine facility quality interventions aimed at improving screening use and performance in collaboration with Projects 1 and 2. In addition, qualitative research that will inform the clinical application of the Program’s innovative risk models will be used to identify barriers and facilitators of clinical adoption in collaboration with Project 3. The CE Core specific aims are to: 1) provide essential methodological expertise and model resources; 2) support evaluation of long-term comparative effectiveness of alternative woman-level screening strategies and facility-level quality intervention strategies to balance benefits, harms, and equity; 3) inform development and clinical application of the Program’s risk models for targeting breast imaging. Research supported by the CE Core will provide information on the most effective and equitable risk-based breast cancer screening and quality improvement strategies. Furthermore, CE Core supported findings will facilitate future dissemination and implementation studies focused on overcoming barriers to risk-based imaging. Centralization of modeling and other specialized services within the CE Core will enhance interactions across all Program components.