Background and objectives: Poverty is associated with greater stroke incidence. The relationship between poverty and stroke recurrence is less clear.
Methods: In this population-based study, incident strokes within the Greater Cincinnati/Northern Kentucky region were ascertained during the 2015 study period and followed up for recurrence until December 31, 2018. The primary exposure was neighborhood socioeconomic status (nSES), defined by the percentage of households below the federal poverty line in each census tract in 4 categories (≤5%, >5%-10%, >10%-25%, >25%). Poisson regression models provided recurrence rate estimates per 100,000 residents using population data from the 2015 5-year American Community Survey, adjusting for age, sex, and race. In a secondary analysis, Cox models allowed for the inclusion of vascular risk factors in the assessment of recurrence risk by nSES among those with incident stroke.
Results: Of 2,125 patients with incident stroke, 245 had a recurrent stroke during the study period. Poorer nSES was associated with increased stroke recurrence, with rates of 12.5, 17.5, 25.4, and 29.9 per 100,000 in census tracts with ≤5%, >5%-10%, >10%-25%, and >25% below the poverty line, respectively (p < 0.01). The relative risk (95% CI) for recurrent stroke among Black vs White individuals was 2.54 (1.91-3.37) before adjusting for nSES, and 2.00 (1.47-2.74) after adjusting for nSES, a 35.1% decrease. In the secondary analysis, poorer nSES (HR 1.74, 95% CI 1.10-2.76 for lowest vs highest category) and Black race (HR 1.31, 95% CI 1.01-1.70) were both independently associated with recurrence risk, though neither retained significance after full adjustment. Age, diabetes, and left ventricular hypertrophy were associated with increased recurrence risk in fully adjusted models.
Discussion: Residents of poorer neighborhoods had a dose-dependent increase in stroke recurrence risk, and neighborhood poverty accounted for approximately one-third of the excess risk among Black individuals. These results highlight the importance of poverty, race, and the intersection of the 2 as potent drivers of stroke recurrence.