Background: Area-level measures are often used to approximate socioeconomic status (SES) when individual-level data are not available. However, no national studies have examined the validity of these measures in approximating individual-level SES. Methods: Data came from ~ 3,471,000 participants in the Mortality Disparities in American Communities study, which links data from 2008 American Community Survey to National Death Index (through 2015). We calculated correlations, specificity, sensitivity, and odds ratios to summarize the concordance between individual-, census tract-, and county-level SES indicators (e.g., household income, college degree, unemployment). We estimated the association between each SES measure and mortality to illustrate the implications of misclassification for estimates of the SES-mortality association. Results: Participants with high individual-level SES were more likely than other participants to live in high-SES areas. For example, individuals with high household incomes were more likely to live in census tracts (r = 0.232; odds ratio [OR] = 2.284) or counties (r = 0.157; OR = 1.325) whose median household income was above the US median. Across indicators, mortality was higher among low-SES groups (all p < .0001). Compared to county-level, census tract-level measures more closely approximated individual-level associations with mortality. Conclusions: Moderate agreement emerged among binary indicators of SES across individual, census tract, and county levels, with increased precision for census tract compared to county measures when approximating individual-level values. When area level measures were used as proxies for individual SES, the SES-mortality associations were systematically underestimated. Studies using area-level SES proxies should use caution when selecting, analyzing, and interpreting associations with health outcomes.

Background: Cancer mortality is higher in counties with high levels of (current) poverty, but less is known about associations with persistent poverty. Persistent poverty counties (with ≥20% of residents in poverty since 1980) face social, structural, and behavioral challenges that may make their residents more vulnerable to cancer. Methods: We calculated 2007 to 2011 county-level, age-adjusted, and overall and type-specific cancer mortality rates (deaths/100,000 people/year) by persistent poverty classifications, which we contrasted with mortality in counties experiencing current poverty (≥20% of residents in poverty according to 2007–2011 American Community Survey). We used two-sample t tests and multivariate linear regression to assess mortality by persistent poverty, and compared mortality rates across current and persistent poverty levels. Results: Overall cancer mortality was 179.3 [standard error (SE) = 0.55] deaths/100,000 people/year in nonpersistent poverty counties and 201.3 (SE = 1.80) in persistent poverty counties (12.3% higher, P < 0.0001). In multivariate analysis, cancer mortality was higher in persistent poverty versus nonpersistent poverty counties for overall cancer mortality as well as for several type-specific mortality rates: lung and bronchus, colorectal, stomach, and liver and intrahepatic bile duct (all P < 0.05). Among counties experiencing current poverty, those counties that were also experiencing persistent poverty had elevated mortality rates for all cancer types as well as lung and bronchus, colorectal, breast, stomach, and liver and intrahepatic bile duct (all P < 0.05). Conclusions: Cancer mortality was higher in persistent poverty counties than other counties, including those experiencing current poverty. Impact: Etiologic research and interventions, including policies, are needed to address multilevel determinants of cancer disparities in persistent poverty counties.