POVERTY OR INCOME INEQUALITY AS PREDICTOR OF MORTALITY - LONGITUDINALCOHORT STUDY

Objectives: To determine the effect of inequality in income between co mmunities independent of household income on individual all cause mort ality in the United States. Design: Longitudinal cohort study. Subject s: A nationally representative sample of 14 407 people aged 25-74 year s in the United States from the first national health and nutrition ex amination survey. Setting: Subjects were followed from initial intervi ew in 1971-5 until 1987. Complete follow up information was available for 92.2% of the sample. Main outcome measures: Relation between both household income and income inequality in community of residence and i ndividual all cause mortality at follow up was examined with Cox propo rtional hazards survival analysis. Results: Community income inequalit y showed a significant association with subsequent community mortality , and with individual mortality after adjustment for age, sex, and mea n income in the community of residence. After adjustment for individua l household income, however, the association with mortality was lost C onclusions: in this nationally representative American sample, family income, but not community income inequality, independently predicts mo rtality. Previously reported ecological associations between income in equality and mortality may reflect confounding between individual fami ly income and mortality.