Proportion of different subtypes of stroke in China

Background and Purpose-The goal of this article is to clarify the proportion of stroke subtypes in China, where stoke is the most common cause of death. Methods-A total of 16 031 first-ever strokes in subjects greater than or equal to 25 years of age were identified in 1991 to 2000 from 17 Chinese populations through a community-based cardiovascular disease surveillance program in the China Multicenter Collaborative Study of Cardiovascular Epidemiology. World Health Organization diagnosis criteria were used for classification of stroke subtypes. Results-CT scan rate of stroke cases reached a satisfactorily high level only after 1996 in the study populations. In 8268 first-ever stroke events from 10 populations with CT scan rate >75% in 1996 to 2000, 1.8% were subarachnoid hemorrhage, 27.5% were intracerebral hemorrhage, 62.4% were cerebral infarction, and 8.3% were undetermined stroke. The proportion of intracerebral hemorrhage varied from 17.1% to 39.4% and that for cerebral infarction varied from 45.5% to 75.9% from population to population. The ratio of ischemic to hemorrhagic stroke ranged from 1.1 to 3.9 and averaged 2.0). The 28-day fatality rate was 33.3% for subarachnoid hemorrhage, 49.4% for intracerebral hemorrhage, 16.9% for cerebral infarction, and 64.6% for undetermined stroke. Conclusions-In our study, ischemic stroke was more frequent and its proportion was higher than hemorrhagic stroke in Chinese populations. Although hemorrhagic stroke was more frequent in Chinese than in Western populations, the variation in the proportion of stroke subtypes among Chinese populations could be as large as or larger than that between Chinese and Western populations.