Using Public Claims Data for Neighborhood Level Epidemiologie Surveillance of Breast Cancer Screening: Findings from Evaluating a Patient Navigation Program in Chicago's Chinatown.

OBJECTIVES: This study was designed to evaluate a patient navigation program undertaken with our community partners in Chicago's Chinatown. Inadvertently, the study collected data on two biannual mammography screening cycles that coincided almost exactly with implementation of the Affordable Care Act (ACA) in Illinois.
METHODS: The study uses claims data to profile mammography screening rates for residents of an 18 zip code, 398 census tract area on Chicago's near south and southwest side. Patient addresses were geocoded from biannual (August 2011 to July 2103 and August 2103 to July 2015) Illinois Medicaid and Illinois Breast and Cervical Cancer Program (IBCCP) claims. Screening rates are presented separately for low-income women ages 40 to 49 and 50 to 64 years. We compare change between 16 tracts with greater than 20% Chinese ancestry, 85 tracts with 1% to 20% Chinese ancestry, and 297 tracts with less than 1% Chinese ancestry.
RESULTS: There were more than 65,000 low-income women age 40 to 64 in the study area (mammogram patients were 63% Black, 23% Hispanic, 10% White, 2.5% Asian, and 2.5% other/unknown race and ethnicity). The increase in screening was greatest in Chinatown, although mean rates were not significantly different across the three areas (p = .07). DISCUSSION: Our results demonstrate large increases in mammography screening after ACA implementation in 20132014. The greatest increase occurred in the Chinatown patient navigation program area. The study provides a template for programs aimed at using public community-area data to evaluate programs for improving access to care and health equity.