Applying Spatial Analyses to Assess Racial/Ethnic Disparities in Access to Breast Cancer Care in Chicago

Background: Racial disparities in breast cancer stage at diagnosis and mortality have persisted since the advent of mammography. Studies suggest structural factors, like access to care, contribute to racial disparities in breast cancer outcomes. This dissertation examined racial/ethnic disparities in spatial access and actual travel burden to breast cancer screening and diagnosing facilities for women in Chicago and their role in breast cancer stage at diagnosis and patterns of diagnostic care. Methods: Data come from the Breast Cancer Care in Chicago population-based study of women diagnosed with breast cancer (N=989). Both driving and public transit-based spatial accessibility measures were created using the Enhanced Two-Step Floating Catchment Area method. Travel burden was measured as travel time via driving and public transit. First, we examined racial/ethnic disparities in spatial accessibility to breast cancer screening and diagnosis facilities by facility type (any facility, Disproportionate Share Hospitals, and Breast Imaging Centers of Excellence). Next, racial/ethnic disparities in actual travel burden for screening and diagnostic services and presentation at Breast Imaging Centers of Excellence (BICOE) were analyzed. Last, we conducted mediation analysis using structural equation modeling to examine the extent to which racial/ethnic disparities in stage at diagnosis and diagnostic patterns of care are explained by spatial accessibility to Breast Imaging Centers of Excellence for screening and diagnostic services. Results: Minority women had less spatial accessibility to any facility and highly accredited BICOE facilities and were less likely to present at BICOE facilities for screening and diagnostic services compared to non-Hispanic white women. Unexpectedly, there were no racial/ethnic difference in actual travel burden to facilities utilized for care. Finally, access to BICOE accounted in part for racial/ethnic disparities in stage at diagnosis (late vs. early), mode of detection (symptomatic vs. screening), and first medical presentation at a BICOE facility. Conclusions: Overall, these findings suggest racial/ethnic disparities in spatial access to highly accredited BICOE facilities play an important role in patterns of diagnostic care and stage at diagnosis.