Persistent Ischemic Stroke Disparities despite Declining Incidence in Mexican Americans

ObjectiveTo determine trends in ischemic stroke incidence among Mexican Americans and non-Hispanic whites. MethodsWe performed population-based stroke surveillance from January 1, 2000 to December 31, 2010 in Corpus Christi, Texas. Ischemic stroke patients 45 years and older were ascertained from potential sources, and charts were abstracted. Neurologists validated cases based on source documentation blinded to ethnicity and age. Crude and age-, sex-, and ethnicity-adjusted annual incidence was calculated for first ever completed ischemic stroke. Poisson regression models were used to calculate adjusted ischemic stroke rates, rate ratios, and trends. ResultsThere were 2,604 ischemic strokes in Mexican Americans and 2,042 in non-Hispanic whites. The rate ratios (Mexican American:non-Hispanic white) were 1.94 (95% confidence interval [CI] = 1.67-2.25), 1.50 (95% CI = 1.35-1.67), and 1.00 (95% CI = 0.90-1.11) among those aged 45 to 59, 60 to 74, and 75 years and older, respectively, and 1.34 (95% CI = 1.23-1.46) when adjusted for age. Ischemic stroke incidence declined during the study period by 35.9% (95% CI = 25.9-44.5). The decline was limited to those aged 60 years, and happened in both ethnic groups similarly (p > 0.10), implying that the disparities seen in the 45- to 74-year age group persist unabated. InterpretationIschemic stroke incidence rates have declined dramatically in the past decade in both ethnic groups for those aged 60 years. However, the disparity between Mexican American and non-Hispanic white stroke rates persists in those <75 years of age. Although the decline in stroke is encouraging, additional prevention efforts targeting young Mexican Americans are warranted. Ann Neurol 2013;74:778-785