Disparities in Premature Mortality Between High- and Low-Income US Counties

The lower the household income, the higher the risk of premature death. That's the principal finding of this study.

Several well-established determinants of health are associated with premature mortality. Using data from the 2010 County Health Rankings, the researchers describe the association of selected determinants of health with premature mortality among counties with broadly differing levels of income.

County-level data on 3,139 U.S. counties from the 2010 County Health Rankings were linked to county mortality data from the Centers for Disease Control and Prevention Compressed Mortality database. These researchers divided counties into three groups, defined by sample median household income levels: low-income (≤25th percentile, $29,631), mid-income (25th-75th percentile, $29,631-$39,401), and high-income (≥75th percentile, ≥$39,401). They analyzed group differences in geographic, sociodemographic, racial/ethnic, health care, social, and behavioral factors. Stratified multivariable linear regression explored the associations of these health determinants with premature mortality for high- and low-income groups.

The association between income and premature mortality was stronger among low-income counties than high-income counties. They found differences in the pattern of risk factors between high- and low-income groups. Significant geographic, sociodemographic, racial/ethnic, health care, social, and behavioral disparities exist among income groups.

Geographic location and the percentages of adult smokers and adults with a college education were associated with premature mortality rates in U.S. counties. These relationships varied in magnitude and significance across income groups. The findings suggest that population health policies aimed at reducing mortality disparities require an understanding of the socioeconomic context within which modifiable variables exist.