Distance to endoscopy services amplifies racial inequities in colorectal cancer mortality in Washington state

Background: This study evaluates relationships among race, access to endoscopy services, and colorectal cancer (CRC) mortality in Washington state (WA). Methods: We overlayed the locations of ambulatory endoscopy services with place of residence at time of death, using Department of Health data (2011–2018). We compared CRC mortality data within and outside a 10 ​km buffer from services. We used linear regression to assess the impact of distance and race on age at death while adjusting for gender and education level. Results: Age at death: median 72.9y vs. 68.2y for white vs. non-white (p ​< ​0.001). The adjusted model showed that non-whites residing outside the buffer died 6.9y younger on average (p ​< ​0.001). Non-whites residing inside the buffer died 5.2y younger on average (p ​< ​0.001), and whites residing outside the buffer died 1.6y younger (p ​< ​0.001). We used heatmaps to geolocate death density. Conclusions: Results suggest that geographic access to endoscopy services disproportionately impacts non-whites in Washington. These data help identify communities which may benefit from improved access to alternative colorectal cancer screening methods.