Abstract 90: Race, Ethnic, and Sex Disparities in Stroke Incidence in the Northern Manhattan Study

Abstract

Background: An excess incidence of strokes among blacks vs whites has been shown previously, but data on disparities related to Hispanic ethnicity remains limited. This study examines race, ethnic, and sex differences in stroke incidence in the multi-ethnic, yet largely Caribbean Hispanic, Northern Manhattan Study (NOMAS). Methods: The study population included participants in the prospective population-based NOMAS, followed for a mean of 13±7 years. Cox proportional hazards models were constructed to estimate the hazard ratios and 95% confidence intervals (HR, 95%CI) for the association between race/ethnicity and sex with confirmed incident stroke of any subtype and ischemic stroke, stratified by age and adjusting for sociodemographics and vascular risk factors. Results: Among 3,298 participants (mean baseline age 69±10, 37% men, 24% black, 21% white, 52% Hispanic), 477 incident strokes accrued (394 ischemic, 43 ICH, 9 SAH). The most common ischemic subtype was cardioembolic, followed by lacunar infarcts, then cryptogenic. The greatest incidence rate was observed in blacks (13/1000 person-years [PY]), followed by Hispanics (11/1000 PY), and lowest in whites (8/1000 PY), and this order was observed for crude incidence rates until age 75. By age 85 the greatest incidence rate was in Hispanics. Blacks had an increased stroke risk vs whites overall in fully adjusted models (HR=1.37, 95% CI=1.02-1.84), and stratified analyses showed that this disparity was driven by women age ≥70 (HR=1.69, 1.05-2.73). The increased rate of stroke observed for Hispanics (age/sex-adjusted HR=1.50, 1.15-1.94) was largely explained by education and insurance status (a proxy for socieoeconomic status; HR after further adjusting for these variables=1.15, 0.84-1.58), but remained significant for women age ≥70. Men had an increased rate of stroke compared to women (fully adjusted HR=1.48, 1.21-1.81). Conclusions: This study provides novel data regarding the increased stroke risk among Caribbean Hispanics. Results highlight the need to create culturally-tailored campaigns to reach blacks and Hispanic populations to reduce race/ethnic stroke disparities, and support the important role of low socioeconomic status in driving an elevated risk among Caribbean Hispanics.