A registry-based approach for estimating county-level race disparities in breast cancer mortality: an analysis in Georgia.

Despite similar incidence rates, nationwide breast cancer mortality is 40% higher among non-Hispanic Black (NHB) than non-Hispanic White (NHW) women. The racial disparity persists even among women with early-stage disease, prognostically favorable subtypes, and indicators of high socioeconomic status and is not evenly distributed throughout the US. Understanding geographic differences may provide additional insight into the drivers of the disparity. However, current data are geographically limited, based primarily on death certificate information, do not incorporate incidence, and often do not provide estimates or account for areas with small populations or sparse case data. Using a Bayesian framework, we estimated the local racial disparity in 5-year mortality for non-metastatic breast cancer diagnosed during 2005-2013 across counties in Georgia, a racially and geographically diverse state. Overall, during the study period, 5-year breast cancer mortality was 43% higher among NHB than NHW women. The racial disparity varied across Georgia with more pronounced disparity observed in the central and southeast and less pronounced disparity in the southwest. Rurality increased and the proportion of owner-occupied housing decreased the magnitude of the disparity, but only after accounting for other area-level covariates. This approach can help guide decisions and resource allocation at the local level.