Ischemic Stroke Subtype Incidence Among Whites, Blacks, and Hispanics

Abstract

Background-Stroke incidence is greater in blacks than in whites; data on Hispanics are limited. Comparing subtype-specific ischemic stroke incidence rates may help to explain race-ethnic differences in stroke risk. The aim of this population-based study was to determine ischemic stroke subtype incidence rates for whites, blacks, and Hispanics living in one community. Methods and Results-A comprehensive stroke surveillance system incorporating multiple overlapping strategies was used to identify all cases of first ischemic stroke occurring between July 1, 1993, and June 30, 1997, in northern Manhattan. Ischemic stroke subtypes were determined according to a modified NINDS scheme, and age-adjusted, race-specific incidence rates calculated. The annual age-adjusted incidence of first ischemic stroke per 100 000 was 88 (95% CI, 75 to 101) in whites, 149 (95% CI, 132 to 165) in Hispanics, and 191 (95% CI, 160 to 221) in blacks. Among blacks compared with whites, the relative rate of intracranial atherosclerotic stroke was 5.85 (95% CI, 1.82 to 18.73); extracranial atherosclerotic stroke, 3.18 (95% CI, 1.42 to 7.13); lacunar stroke, 3.09 (95% CI, 1.86 to 5.11); and cardioembolic stroke, 1.58 (95% CI, 0.99 to 2.52). Among Hispanics compared with whites, the relative rate of intracranial atherosclerotic stroke was 5.00 (95% CI, 1.69 to 14.76); extracranial atherosclerotic stroke, 1.71 (95% CI, 0.80 to 3.63); lacunar stroke, 2.32 (95% CI, 1.48 to 3.63); and cardioembolic stroke, 1.42 (95% CI, 0.97 to 2.09). Conclusions-The high ischemic stroke incidence among blacks and Hispanics compared with whites is due to higher rates of all ischemic stroke subtypes.

Trends in Acute Ischemic Stroke Hospitalizations in the United States

“…Our findings are consistent with prior studies demonstrating higher AIS hospitalizations in blacks and Hispanics compared to whites 6, 8, 9, 10, 29. AIS hospitalization rates were greatest in blacks throughout the decade, and in 2010 were more than double the hospitalization rates of both whites and Hispanics.…”

“…AIS rates were 2‐fold greater in young black versus white women and men in Baltimore County,29 higher in blacks compared to whites in the Greater Cincinnati/Northern Kentucky Stroke Study,6 and higher in Mexican Americans compared to non‐Hispanic whites in the Brain Attack Surveillance in Corpus Christi Project 10. Data from the Northern Manhattan Stroke Study showed that the annual incidence of first AIS from 1993 to 1997 was greatest in blacks, followed by Hispanics (mainly of Caribbean origin) and whites 8. The age‐adjusted AIS hospitalization rates in Florida for individuals aged 25 to 49 years was greatest in blacks, followed by whites, then Hispanics (mainly Cuban, Puerto Rican, Mexican, and South Americans in origin) regardless of sex 9…”

“…The disparity was less pronounced between Hispanics and whites. In the Northern Manhattan population, AIS hospitalization rates for mainly Caribbean Hispanics were 1.7 times higher8 than whites and in a mainly Mexican community in Texas, 1.2 times higher than whites 10. In Florida, on the other hand, AIS hospitalization rates among a heterogeneous Hispanic population of Cubans, Puerto Ricans, Mexicans, and South Americans were 30% lower than whites 9…”

“…Racial/ethnic disparities in acute ischemic stroke (AIS) hospitalizations have been well described for specific populations in the United States. Multiple studies in the 1990s and 2000s revealed high black–white disparities, with AIS hospitalization rates 1.5 to 2.5 times higher in blacks 6, 7, 8, 9. The disparity was less pronounced between Hispanics and whites.…”

Racial‐Ethnic Disparities in Acute Stroke Care in the Florida‐Puerto Rico Collaboration to Reduce Stroke Disparities Study

“…Disparities exist in stroke mortality, morbidity, prevalence of biological and environmental risk factors, healthcare access, and quality of care. Incidence data from NOMAS (the Northern Manhattan Study) has demonstrated racial‐ethnic differences in stroke incidence, with blacks and Hispanics having more than a 2‐fold increase in annual stroke incidence compared with whites 4, 5. Some studies have documented disparities in access to acute stroke care, activation of 911 services, delayed arrival to the emergency department, longer waiting times, and treatment delays in thrombolysis 3.…”