Rural-urban disparities in colorectal cancer screening in United States: Blinder-Oaxaca decomposition analysis of...

Colorectal cancer (CRC) remains a leading cause of cancer mortality in the United States. While screening significantly reduces CRC incidence and mortality, disparities persist, particularly between rural and urban populations. This study assessed the extent and determinants of rural-urban disparities in CRC screening using nationally representative data from the Behavioral Risk Factor Surveillance System (BRFSS) between 2019 and 2023.

The study analyzed responses from 535,568 adults using complex survey-weighted logistic regression and Blinder-Oaxaca decomposition analysis. CRC screening status was defined as a binary outcome. Independent variables included geographic classification (rural and urban), age, sex, race/ethnicity, education, income, insurance status, and access to a personal healthcare provider.

Overall, 73.0% of eligible adults reported undergoing CRC screening, with a higher prevalence among urban residents (77.7%) than rural residents (74.4%). Decomposition analysis revealed that 27.5% of the rural-urban disparity was attributable to differences in measurable characteristics such as education, income, age distribution, insurance, and provider access. Educational attainment and income contributed most to the explained gap. However, 72.5% of the disparity remained unexplained, indicating potential influences from structural, cultural, and healthcare system-level factors.

Substantial rural-urban disparities in CRC screening persist, largely driven by unmeasured contextual factors. Addressing this gap requires multifaceted, equity-focused interventions. Future research should adopt the socio-ecological model to comprehensively examine multilevel determinants influencing screening behaviors, especially within underserved rural communities.