Epidemiology of stroke and its subtypes in Chinese vs white populations: a systematic review

Abstract

Objective: We aimed to systematically assess the evidence for differences in the incidence of stroke and distribution of its subtypes in Chinese compared with white populations.

Methods: We comprehensively sought studies conducted since 1990 in Chinese populations of 1) first-ever stroke incidence (community-based studies only), and 2) pathologic types/subtypes of stroke (hospital- or community-based studies of first-ever or recurrent strokes). We identified community-based studies in white populations from a recent systematic review. For each study, we calculated age-standardized stroke incidence and the proportions of each pathologic type and ischemic subtype, using random-effects meta-analysis to pool proportions of stroke types/subtypes in Chinese and in white populations.

Results: Age-standardized annual first-ever stroke incidence in community-based studies was higher among Chinese than white populations (for ages 45-74 years, range 205-584 vs 170-335 per 100,000, respectively). Intracerebral hemorrhage accounted for a larger, more variable proportion of strokes in China than Taiwan (range 27%-51% vs 17%-28%), in Chinese community-based than hospital-based studies (27%-51% vs 17%-30%), and in community-based Chinese than white studies (pooled proportion 33% vs 12%). Although the overall proportion of lacunar ischemic stroke appeared higher in Chinese than white populations, variable study methodologies precluded reliable comparisons.

Conclusions: There is good evidence for a slightly higher overall stroke incidence and higher proportion of intracerebral hemorrhage in Chinese vs white populations, but no clear evidence for different distributions of ischemic stroke subtypes. Studies using comparable, population-based case ascertainment and similar classification methods are needed to address this.

Figure 1. Age-standardized incidence (per 100,000 person-years) in Chinese and white populations

Age-standardized incidence (per 100,000 person-years) for (A) ages 45–74 years and (B) ages 45–75+ years. Confidence interval could not be calculated in one study because the number of strokes in each age-specific group was not available.^e3

Figure 2. Distributions of stroke pathologic and ischemic subtypes in Chinese and white populations

(A) Stroke pathologic types. (B) Ischemic stroke subtypes by TOAST classification. (C) Ischemic stroke subtypes by OCSP classification. C = community-based; CE = cardioembolism; H = hospital-based; ICH = intracerebral hemorrhage; IS = ischemic stroke; L = large-artery atherosclerosis; LACI = lacunar infarct; O = other determined etiology; OCSP = Oxfordshire Community Stroke Project; PACI = partial anterior circulation infarct; POCI = posterior circulation infarct; S = small-vessel occlusion; SAH = subarachnoid hemorrhage; TACI = total anterior circulation infarct; TOAST = Trial of Org 10172 in Acute Ischemic Stroke; U = undetermined etiology; UC = unclassified. *Study in 1995.^e13 **Study in 1997.^e8