Socioeconomic status and stroke incidence in the US elderly: the role of risk factors in the EPESE study

Abstract

Background and purpose: This study assesses the effect of socioeconomic status on stroke incidence in the elderly, and the contribution of risk factors to stroke disparities.

Methods: Data comprised a sample of 2812 men and women aged 65 years and over from the New Haven cohort of the Established Populations for the Epidemiologic Studies of the Elderly. Individuals provided baseline information on demographics, functioning, cardiovascular and psychosocial risk factors in 1982 and were followed for 12 years. Proportional hazard models were used to model survival from initial interview to first fatal or nonfatal stroke.

Results: Two hundred and seventy subjects developed incident stroke. At ages 65 to 74, lower socioeconomic status was associated with higher stroke incidence for both education (HR(lowest/highest)=2.07, 95% CI, 1.04 to 4.13) and income (HR(lowest/highest)=2.08, 95% CI, 1.01 to 4.27). Adjustment for race, diabetes, depression, social networks and functioning attenuated hazard ratios to a nonsignificant level, whereas other risk factors did not change associations significantly. Beyond age 75, however, stroke rates were higher among those with the highest education (HR(lowest/highest)=0.42, 95% CI, 0.22 to 0.79) and income (HR(lowest/highest)=0.43, 95% CI, 0.22 to 0.86), which remained largely unchanged after adjustment for risk factors.

Conclusions: We observed substantial socioeconomic disparities in stroke at ages 65 to 74, whereas a crossover of the association occurred beyond age 75. Policies to improve social and economic resources at early old age, and interventions to improve diabetes management, depression, social networks and functioning in the disadvantaged elderly can contribute to reduce stroke disparities.