Association Between Social Vulnerability and Gastrointestinal Cancer Mortality in the United States Counties

Social determinants of health contribute to disparities in gastrointestinal (GI) cancer mortality between individuals in the US. Their effects on count-level mortality rates remain uncertain. We aimed to assess the association between county social vulnerability and GI cancer mortality.

In this ecological study (2016-2020), we obtained US county Social Vulnerability Index (SVI) from the Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry and age-adjusted mortality rates (AAMRs) for GI cancers from Centers for Disease Control and Prevention WONDER (Wide-Ranging Online Data for Epidemiological Research). SVI ranges from 0 to 1, with higher indices indicating greater vulnerability. We presented AAMRs by quintiles of SVIs. We used Poisson regression through generalized estimating equation to calculate rate ratios (RRs) and 95% confidence intervals (CIs) for GI cancer mortality by quintiles of SVI.

There were 799,968 deaths related to GI cancers from 2016 to 2020, resulting in an AAMR (95% CI) of 39.9 (41.4-51.2) deaths per 100,000 population. The largest concentration of counties with greater SVI and GI cancer mortality was clustered in the southern US. Counties with greater SVI had higher mortality related to all GI cancers (RR_{Q5 vs Q1}, 1.19 [95% CI, 1.14-1.24]), gastric cancer (1.58 [1.48-1.69]), liver cancer (1.54 [1.36-1.73]), and colorectal cancer (RR_{Q5 vs Q1}, 1.23 [95% CI, 1.15-1.31]). RRs for overall GI cancers were greater among individuals <45 years (1.24 [1.15-1.32]), men (1.22 [1.16-1.27]), Hispanic individuals (1.33 [1.18-1.50]), and rural counties (1.21 [1.14-1.27]) compared with their counterparts.

Socially disadvantaged counties face a disproportionately high burden of GI cancer mortality in the US. Targeted public health interventions should aim to address social inequities faced by underserved communities.