Social Determinants of Health Impact Rural–Urban Disparity in CRC Mortality

WEDNESDAY, Dec. 3, 2025 (HealthDay News) — The rural–urban colorectal cancer (CRC) mortality disparity is mainly driven by specific social determinants of health, including low socioeconomic status, according to a study published online Nov. 24 in Cancer.

Sara Myers, M.D., from Boston Medical Center, and colleagues examined the contribution of each Social Vulnerability Index (SVI) component to CRC mortality disparities among rural and urban counties. Rural–urban differences in county demographics and in 14 SVI factors were examined for all U.S. counties from 1999 to 2020. The proportion of rural–urban CRC mortality disparity mediated by the SVI was estimated.

Data were included from 2,927 counties (60.7 percent rural and 39.3 percent urban). The researchers found that rural counties had 11.8 percent higher CRC mortality than urban counties; 18.6, 8.8, and 2.7 percent of that disparity was mediated by low socioeconomic status, household characteristics, and racial/ethnic minority status, respectively. Poverty, unemployment, lacking a high school diploma, household crowding, and lacking a vehicle had the greatest impact on CRC mortality among all counties (incidence rate ratios, 3.2, 5.4, 2.7, 3.3, and 3.4, respectively). Lacking a vehicle was associated with higher CRC mortality among rural versus urban counties (incidence rate ratios, 4.3 and 1.9, respectively).

“Our findings show that while socioeconomic vulnerability drives much of the disparity in colorectal cancer mortality, the rural–urban gap is shaped by a broader set of contextual factors,” senior author Kelly M. Kenzik, Ph.D., from Brigham and Women”s Hospital in Boston, said in a statement.

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