County-Level CRC Mortality Disparities Linked to Broadband Gaps, Smoking, and Rurality

Counties with the least broadband access, the highest smoking rates, and nonmetropolitan status had significantly higher colorectal cancer (CRC) mortality than their better-connected, urban counterparts, according to a nationwide ecological analysis recently published in Frontiers in Oncology.¹

Examining County-Level Differences in CRC Outcomes

As CRC continues to contribute substantially to the US cancer burden overall, persistent geographic disparities in incidence and mortality exist across counties, with some communities experiencing disproportionately high disease burdens. These disparities may reflect differences in socioeconomic conditions, health behaviors, rurality, and access to preventive and follow-up care.

Since health care is increasingly relying on digital tools such as patient portals and telehealth, researchers noted that broadband internet access may play a role in a community’s ability to navigate care. However, they highlighted that this relationship has not been well characterized alongside other correlated socioeconomic, behavioral, and rurality factors.

To address this knowledge gap, investigators conducted a nationwide county-level ecological study with 3 objectives: characterize county-level variation in CRC mortality and differences between high- and low-burden counties; estimate core-adjusted associations of social, preventive care, behavioral, and rurality indicators with CRC mortality; and compare key associations across CRC mortality, all-cancer mortality, and CRC incidence.

The study linked county-level data from CDC PLACES, the American Community Survey, US Cancer Statistics, and the 2023 National Center for Health Statistics urban-rural classification scheme. Researchers used population-weighted linear regression models with state fixed effects to evaluate both age-adjusted CRC mortality and all-cancer mortality from 2019 to 2023, as well as CRC incidence from 2018 to 2022. Models adjusted for the county proportion of residents aged 65 years or older, with nonmetropolitan status also included where applicable.

What Drove Higher CRC Mortality

The final analytic samples included 2126 counties for CRC mortality, 3005 for all-cancer mortality, and 2628 for CRC incidence. Counties with a 1-standard-deviation higher prevalence of residents lacking broadband internet access had a CRC mortality rate 1.82 per 100,000 population higher (95% CI, 1.44-2.20). Higher current smoking prevalence was associated with a 2.08-per-100,000 higher CRC mortality rate (95% CI, 1.74-2.42), while nonmetropolitan counties had a 2.73-per-100,000 higher CRC mortality rate than metropolitan counties (95% CI, 2.35-3.11).

Other social determinants associated with higher CRC mortality included poverty below 150% of the federal poverty level, lack of a high school diploma, unemployment, high housing cost burden, and single-parent households. Obesity, short sleep duration, and physical inactivity were also positively associated with CRC mortality.

Compared with counties in the lowest CRC mortality quartile, those in the highest had more residents living below 150% of the poverty level (29.31% vs 18.69%) and lacking broadband access (23.35% vs 13.28%). The highest-mortality quartile also had a current smoking prevalence approximately 6.5 percentage points higher than the lowest quartile (21.98% vs 15.44%).

Preventive Care Engagement Associated With Better CRC Outcomes

By contrast, higher up-to-date CRC screening prevalence was associated with lower CRC mortality (β = –1.64; 95% CI, –1.97 to –1.31), as was a higher prevalence of recent dental visits among residents (β = –1.84; 95% CI, –2.27 to –1.40). Although dental visits are not a CRC prevention intervention, the researchers noted that they may serve as a proxy for broader routine health care engagement. Similar directional patterns were observed for all-cancer mortality and CRC incidence.

Overall, broadband deprivation, current smoking, and nonmetropolitan status were associated with worse outcomes across all 3 measures, whereas higher screening uptake and dental visit prevalence were associated with lower mortality and incidence. The consistency of these patterns suggests a broader geographic cancer disadvantage rather than CRC-specific mechanisms alone, the researchers highlighted.

The findings add to a growing body of research on rural CRC disparities. A recent Blinder-Oaxaca decomposition analysis found that rural residents had lower CRC screening rates than urban residents (74.4% vs 77.7%), with more than 70% of that gap unexplained by measurable sociodemographic or access factors.² In addition, limited broadband access can restrict the reach of telehealth and digital tools intended to address rural cancer care gaps, with rural oncology leaders describing connectivity as a prerequisite for extending high-tech cancer care beyond urban centers.³

Integrated Strategies Needed to Address County-Level CRC Disparities

The authors acknowledged several limitations, including the study’s ecological and cross-sectional design, which prevents causal inference and raises the possibility of ecological fallacy.¹ In addition, CRC mortality had the most unavailable or suppressed county-level rates compared with the other outcomes, reducing the primary analytic sample and potentially introducing selection bias. Still, they noted that the findings point toward the need for strategies that address multiple contributors to geographic cancer disparities.

“Similar directional patterns across CRC mortality, all-cancer mortality, and CRC incidence suggest that these contextual indicators may reflect broader geographic cancer disadvantage rather than CRC-specific mechanisms alone,” the authors concluded. “Integrated structural, preventive care, behavioral, and rural health strategies may help reduce county-level disparities in CRC outcomes.”

References

1. Xia K, Luo L, Fan C, Zhang H, Yang X, Lin C. County-level social, preventive care, and behavioral correlates of colorectal cancer mortality in the United States: a nationwide ecological analysis. Front Oncol. 2026;16:1844633. doi:10.3389/fonc.2026.1844633
2. Steinzor P. Rural-urban disparities in colorectal cancer screening persist. AJMC^®. September 21, 2025. Accessed August 19, 2026. https://www.ajmc.com/view/rural-urban-disparities-in-colorectal-cancer-screening-persist
3. Santoro C. Bridging the digital divide of rural cancer care with telehealth. AJMC. October 21, 2024. Accessed August 19, 2026. https://www.ajmc.com/view/bridging-the-digital-divide-of-rural-cancer-care-with-telehealth