Education, income, and incident heart failure in post-menopausal women: the Women's Health Initiative Hormone Therapy Trials

Abstract

Objectives: The purpose of this study is to estimate the effect of education and income on incident heart failure (HF) hospitalization among post-menopausal women.

Background: Investigations of socioeconomic status have focused on outcomes after HF diagnosis, not associations with incident HF. We used data from the Women's Health Initiative Hormone Trials to examine the association between socioeconomic status levels and incident HF hospitalization.

Methods: We included 26,160 healthy, post-menopausal women. Education and income were self-reported. Analysis of variance, chi-square tests, and proportional hazards models were used for statistical analysis, with adjustment for demographics, comorbid conditions, behavioral factors, and hormone and dietary modification assignments.

Results: Women with household incomes <$20,000 a year had higher HF hospitalization incidence (57.3/10,000 person-years) than women with household incomes >$50,000 a year (16.7/10,000 person-years; p < 0.01). Women with less than a high school education had higher HF hospitalization incidence (51.2/10,000 person-years) than college graduates and above (25.5/10,000 person-years; p < 0.01). In multivariable analyses, women with the lowest income levels had 56% higher risk (hazard ratio: 1.56, 95% confidence interval: 1.19 to 2.04) than the highest income women; women with the least amount of education had 21% higher risk for incident HF hospitalization (hazard ratio: 1.21, 95% confidence interval: 0.90 to 1.62) than the most educated women.

Conclusions: Lower income is associated with an increased incidence of HF hospitalization among healthy, post-menopausal women, whereas multivariable adjustment attenuated the association of education with incident HF.