INCOME-DISTRIBUTION AND MORTALITY - CROSS-SECTIONAL ECOLOGICAL STUDY OF THE ROBIN-HOOD INDEX IN THE UNITED-STATES

Objective-To determine the effect of income inequality as measured by the Robin Hood index and the Gini coefficient on all cause and cause s pecific mortality in the United States. Design-Cross sectional ecologi cal study. Setting-Households in the United States. Main outcome measu res-Disease specific mortality, income, household size, poverty, and s moking rates for each state. Results-The Robin Hood index was positive ly correlated with total mortality adjusted for age (r = 0 . 54; P < 0 . 05). This association remained after adjustment for poverty (P < 0 . 007), where each percentage increase in the index was associated wit h an increase in the total mortality of 21 . 68 deaths per 100000. Eff ects of the index were also found for infant mortality (P = 0 . 013); coronary heart disease (P = 0 . 004); malignant neoplasms (P = 0 . 023 ); and homicide (P < 0 . 001). Strong associations were also found bet ween the index and causes of death amenable to medical intervention. T he Gini coefficient showed very little correlation with any of the cau ses of death. Conclusion-Variations between states in the inequality o f income were associated with increased mortality from several causes. The size of the gap between the wealthy and less well off-as distinct from the absolute standard of living enjoyed by the poor-seems to mat ter in its own right. The findings suggest that policies that deal wit h the growing inequities in income distribution may have an important impact on the health of the population.