State-level income inequality and individual mortality risk: a prospective, multilevel study

Am J Public Health. 2001 Mar;91(3):385-91. doi: 10.2105/ajph.91.3.385.

Abstract

Objectives: Previous studies have linked state-level income inequality to mortality rates. However, it has been questioned whether the relationship is independent of individual-level income. The present study tests whether state-level income inequality is related to individual mortality risk, after adjustment for individual-level characteristics.

Methods: In this prospective, multilevel study design, the vital status of National Health Interview Survey (NHIS) respondents was ascertained by linkage to the National Death Index, with additional linkage of state-level data to individuals in the NHIS. The analysis included data for 546,888 persons, with 19,379 deaths over the 8-year follow-up period. The Gini coefficient was used as the measure of income inequality.

Results: Individuals living in high-income-inequality states were at increased risk of mortality (relative risk = 1.12; 95% confidence interval = 1.04, 1.19) compared with individuals living in low-income-inequality states. In stratified analyses, significant effects of state income inequality on mortality risk were found, primarily for near-poor Whites.

Conclusions: State-level income inequality appears to exert a contextual effect on mortality risk, after income is adjusted for, providing further evidence that the distribution of income is important for health.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • African Americans / statistics & numerical data
  • Aged
  • European Continental Ancestry Group / statistics & numerical data
  • Female
  • Humans
  • Income*
  • Male
  • Middle Aged
  • Mortality*
  • Prospective Studies
  • Risk Factors
  • United States