title: Incidence and risks of subarachnoid hemorrhage in China.
abstract: OBJECTIVE
  To determine incidence and risks of subarachnoid hemorrhage in China.
  
  
  METHODS
  A prospective, population-based, 1:2 matched case-control study in Baotou, Inner Mongolia (≈2 million population) in 2009-2011. Multiple variable models used to determine relative risk and population-attributable risks for exposures.
  
  
  RESULTS
  For a total of 226 patients (mean age, 59 years; 65% women; 434 controls), crude annual incidence (per 100 000) of subarachnoid hemorrhage was 6.2 (95% confidence intervals, 5.4-7.0); 4.3 (3.3-5.2) for men and 8.2 (6.9-9.6) for women. Compared with nonsmokers, adjusted relative risk of subarachnoid hemorrhage in current smokers was 2.31 (95% confidence interval, 1.31-4.09) but was 4.00 (1.62-9.89) in women. Population-attributable risk for smoking, hypertension, and low income were 18%, 36% and 59%, respectively.
  
  
  CONCLUSIONS
  The incidence of subarachnoid hemorrhage in China is slightly lower than in Western countries and is related to smoking, hypertension, and poor socioeconomic status.
authors.affiliation: From the Department of Neurology, Baotou Central Hospital, Baotou, Inner Mongolia, China (J.Z., G.L., Y.L., G.C., L.L.); The George Institute for Global Health and the University of Sydney, Australia (H.A., I.S., C.S.A.); Department of Neurology, Baogang Hospital, Baotou, Inner Mongolia, China (H.W.); Department of Neurology, The 1st affiliated Hospital of Baotou Medical College, Baotou, Inner Mongolia, China (C.Z.); Department of Neurology, Baotou No 4 Hospital, Baotou, Inner Mongolia, China (J.Z.); and Department of Neurosciences, Royal Prince Alfred Hospital, Sydney, Australia (C.S.A.).
authors.forename: Jingfen
authors.initials: J
authors.lastname: Zhang
authors.forename: Guorong
authors.initials: G
authors.lastname: Liu
authors.forename: Hisatomi
authors.initials: H
authors.lastname: Arima
authors.forename: Yuechun
authors.initials: Y
authors.lastname: Li
authors.forename: Guojuan
authors.initials: G
authors.lastname: Cheng
authors.forename: Ivy
authors.initials: I
authors.lastname: Shiue
authors.forename: Lin
authors.initials: L
authors.lastname: Lv
authors.forename: Huiling
authors.initials: H
authors.lastname: Wang
authors.forename: Chunyang
authors.initials: C
authors.lastname: Zhang
authors.forename: Jianchun
authors.initials: J
authors.lastname: Zhao
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology* / Q000209:etiology
keywords: China; epidemiology; hypertension; incidence; risk factors; subarachnoid hemorrhage