Temporal Trends in Ischemic Stroke Rates by Ethnicity, Sex, and Age 2000-2017: The Brain Attack Surveillance in Corpus Christi Project.

OBJECTIVE: To compare 18-year (2000-2017) temporal trends in ischemic stroke rates by ethnicity, sex and age. METHODS: Data are from a population-based stroke surveillance study conducted in Nueces County, Texas, USA, a geographically isolated, bi-ethnic, urban community. Active (screening hospital admission logs, hospital wards, intensive care units) and passive (screening inpatient/ED discharge diagnosis codes) surveillance were used to identify cases aged ≥45 (n=4,874) validated by stroke physicians using a consistent stroke definition over time. Ischemic stroke rates were derived from Poisson regression using annual population counts from US Census to estimate at-risk population. RESULTS: In those aged 45-59, rates increased in non-Hispanic Whites (104.3% relative increase; p<0.001) but decreased in Mexican Americans (-21.9%; p=0.03) such that rates were significantly higher in non-Hispanic Whites in 2016-2017 (p for ethnicity-time interaction<0.001). In those age 60-74, rates declined in both groups but more so in Mexican Americans (non-Hispanic Whites -18.2%, p=0.05; Mexican Americans -40.1%, p=0.002) resulting in similar rates for the two groups in 2016-2017 (p for ethnicity-time interaction=0.06). In those aged ≥75, trends did not vary by ethnicity, with declines noted in both groups (non-Hispanic Whites -33.7%, p=0.002; Mexican Americans -26.9%, p=0.02). Decreases in rates were observed in men (age 60-74 -25.7%, p=0.009; age ≥75 -39.2% p=0.002) and women (age 60-74 -34.3%, p=0.007; age ≥75 -24.0% p=0.02) in the two older age groups, while rates did not change in either sex in those age 45-59. INTERPRETATION: Previously documented ethnic stroke incidence disparities have ended as a result of declining rates in Mexican Americans and increasing rates in non-Hispanic whites, most notably in midlife.