title: Cognitive impairment and risk of future stroke: a systematic review and meta-analysis.
abstract: BACKGROUND
  Several studies have assessed the link between cognitive impairment and risk of future stroke, but results have been inconsistent. We conducted a systematic review and meta-analysis of cohort studies to determine the association between cognitive impairment and risk of future stroke.
  
  
  METHODS
  We searched MEDLINE and Embase (1966 to November 2013) and conducted a manual search of bibliographies of relevant retrieved articles and reviews. We included cohort studies that reported multivariable adjusted relative risks and 95% confidence intervals or standard errors for stroke with respect to baseline cognitive impairment.
  
  
  RESULTS
  We identified 18 cohort studies (total 121 879 participants) and 7799 stroke events. Pooled analysis of results from all studies showed that stroke risk increased among patients with cognitive impairment at baseline (relative risk [RR] 1.39, 95% confidence interval [CI] 1.24-1.56). The results were similar when we restricted the analysis to studies that used a widely adopted definition of cognitive impairment (i.e., Mini-Mental State Examination score < 25 or nearest equivalent) (RR 1.64, 95% CI 1.46-1.84). Cognitive impairment at baseline was also associated with an increased risk of fatal stroke (RR 1.68, 95% CI 1.21-2.33) and ischemic stroke (RR 1.65, 95% CI 1.41-1.93).
  
  
  CONCLUSIONS
  Baseline cognitive impairment was associated with a significantly higher risk of future stroke, especially ischemic and fatal stroke.
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Meng
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Saver
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Keun-Sik
authors.initials: KS
authors.lastname: Hong
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Yi-Ling
authors.initials: YL
authors.lastname: Wu
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Hsing-Cheng
authors.initials: HC
authors.lastname: Liu
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC.
authors.forename: Neal M
authors.initials: NM
authors.lastname: Rao
authors.affiliation: Department of Neurology (Lee, Wu), Chang Gung University College of Medicine, Chang Gung Memorial Hospital, Chiayi, Taiwan; Stroke Center and Department of Neurology (Saver, Rao), Geffen School of Medicine, University of California, Los Angeles; Department of Neurology (Hong), Ilsan Paik Hospital, Inje University, Gimhae, South Korea; Department of Psychiatry (Liu), Taipei City Hospital Song-Te Branch, Taipei, Taiwan; Department of Neurosciences (Ovbiagele), Medical University of South Carolina, Charleston, SC ovibes@musc.edu.
authors.forename: Bruce
authors.initials: B
authors.lastname: Ovbiagele
mesh_terms: D060825:Cognitive Dysfunction / Q000150:complications*; D006801:Humans; D012307:Risk Factors; D020521:Stroke / Q000209:etiology*