Race/Ethnicity and Income Disparities in US Adult Mortality

Objectives: The objectives of the study were to investigate associations between socioeconomic status and all-cause mortality in the United States, and racial/ethnic differences in this association. We stratify analysis by race/ethnicity to test whether the consequences of SES variables are more pronounced among certain racial/ethnic groups than others.
Methods: Data employed were obtained from the National Longitudinal Mortality Study. It is a study of respondents in the Current Population Surveys of the early 1980s whose mortality experiences were followed through the 1990s. The sample includes 707169 individuals aged 18 and above at baseline of which 88489 had died at the end of the 11 year follow-up period. Proportional hazards regression models were fitted to the data.
Results: The socioeconomic variables education and income were strongly associated with all-cause mortality. Persons with less than high school education were 64% (ARR=1.64, 95% CI=1.58, 1.70) more likely to die than those with graduate or professional education. Individuals making less than $10,000 per year were 59% more likely to die during the follow up period than their counterparts making $60,000 or more (ARR=1.59, 95% CI=1.54, 1.65). Persons without health insurance were 14% as likely to die as those with health insurance (ARR=1.14, 95% CI=1.13, 1.16).
Conclusion: Results were generally consistent with past studies on the contribution of SES to mortality. This was the first study to note that the effects of SES on mortality vary significantly by racial/ethnic groups. Although college education is a much stronger predictor of mortality among whites, it is not a strong mortality covariate among African Americans and Hispanics. Among African Americans, low income has more devastating consequences than it does among Whites. Future studies on the SES-mortality relationship ought to stratify samples by race in order to get a more accurate understanding of the effects of SES.