Individual income, income inequality, health, and mortality: what are the relationships?

Abstract

Objective: To examine the pathways between income inequality, self-rated health, and mortality in the United States.

Data source: The first National Health and Nutrition Examination Survey and Epidemiologic Follow-up Study.

Design: This was a longitudinal, multilevel study.

Data collection: Baseline data were collected on county income inequality, individual income, age, sex, self-rated health, level of depressive symptoms, and severity of biomedical morbidity from physical examination. Follow-up data included self-rated health assessed in 1982 through 1984 and mortality through 1987.

Principal findings: After adjustment for age and sex, income inequality had a modest independent effect on the level of depressive symptoms, and on baseline and follow-up self-rated health, but no independent effect on biomedical morbidity or subsequent mortality. Individual income had a larger effect on severity of biomedical morbidity, level of depressive symptoms, baseline and follow-up self-rated health, and mortality.

Conclusion: Income inequality appears to have a small effect on self-rated health but not mortality; the effect is mediated in part by psychological, but not biomedical pathways. Individual income has a much larger effect on all of the health pathways.