title: [The incidence of ischemic and hemorrhagic stroke in Chinese populations].
abstract: OBJECTIVE
  To study the ratio of ischemic to hemorrhagic stroke incidence in Chinese populations.
  
  
  METHODS
  Fifteen populations in China, each including about 100,000 residents, were monitored from 1991 to 2000 for the occurrence of stroke. Stroke was classified as hemorrhagic, ischemic and unclassified based on the clinical data and CT scan results respectively.
  
  
  RESULTS
  The average CT scan rate in stroke patients from 1996 to 2000 varied from 14.8% to 97.5% among the 15 population and the average ratio of ischemic to hemorrhagic stroke ranged from 0.23:1 to 4.38:1; the correlation coefficient between the ratio and CT scan rate is 0.7 (P = 0.003). In all the populations with CT scan rate greater than 80%, the ischemic to haemorrhagic ratios were all greater than 1.0. From 1991 to 2000 in 12 populations with complete data, the CT scan rate in stroke patients rose from 41.1% to 88.3% and the ischemic to hemorrhagic ratio rose from 1.25:1 to 1.85:1. The correlation coefficient between the ratio and the CT scan rate was 0.9 (P < 0.001). In patients having CT scan, the ischemic to hemorrhagic ratio was greater than 1.0 in all the years.
  
  
  CONCLUSIONS
  The predominant type of stroke in Chinese population is ischemic. The low CT scan rate in some populations is the main reason for the false impression predominantly hemorrhagic stroke.
authors.affiliation: Department of Epidemiology, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China.
authors.forename: Lin-feng
authors.initials: LF
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Yang-feng
authors.initials: YF
authors.lastname: Wu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hong
authors.forename: Guang-gu
authors.initials: GG
authors.lastname: Yuan
authors.forename: Bei-fan
authors.initials: BF
authors.lastname: Zhou
authors.forename: Lian-cheng
authors.initials: LC
authors.lastname: Zhao
authors.forename: Yi-ning
authors.initials: YN
authors.lastname: Huang
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology*; D014057:Tomography, X-Ray Computed