title: Thrombocytopenia and in-hospital mortality risk among ischemic stroke patients.
abstract: BACKGROUND
  Thrombocytopenia has been associated with increased mortality in nonstroke conditions. Because its role in acute ischemic stroke is less well understood, we sought to determine whether thrombocytopenia at admission for acute ischemic stroke was associated with in-hospital mortality.
  
  
  METHODS
  We used data from a retrospective cohort of stroke patients (1998-2003) at 5 U.S. hospitals. Risk factors considered included conditions that can lead to thrombocytopenia (e.g., liver disease), increase bleeding risk (e.g., hemophilia), medications with antiplatelet effects (e.g., aspirin), and known predictors of mortality (e.g., National Institutes of Health Stroke Scale and Charlson Comorbidity Index scores). Logistic regression modeling evaluated the adjusted association between thrombocytopenia, defined as platelets <100,000/μL, and in-hospital mortality.
  
  
  RESULTS
  Among 1233 acute ischemic stroke patients, thrombocytopenia was present in 2.3% (n = 28). A total of 6.1% (n = 75) of patients died in the hospital. In unadjusted analyses, thrombocytopenia was associated with higher mortality (8/28 [28.6%] v 67/1205 [5.6%]; P < .0001). Thrombocytopenia was also independently associated with in-hospital mortality after adjustment for National Institutes of Health Stroke Scale score and comorbidities, with an odds ratio of 6.6 (95% confidence interval 2.3-18.6).
  
  
  CONCLUSIONS
  Admission thrombocytopenia among patients presenting with acute ischemic stroke predicts in-hospital mortality.
authors.affiliation: Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; Neurology Service, Veterans Health Administration Connecticut Healthcare System, West Haven, Connecticut; Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut. Electronic address: jason.sico@va.gov.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Sico
authors.forename: Michael S
authors.initials: MS
authors.lastname: Phipps
authors.forename: John
authors.initials: J
authors.lastname: Concato
authors.forename: Carolyn K
authors.initials: CK
authors.lastname: Wells
authors.forename: Albert C
authors.initials: AC
authors.lastname: Lo
authors.forename: Steven E
authors.initials: SE
authors.lastname: Nadeau
authors.forename: Linda S
authors.initials: LS
authors.lastname: Williams
authors.forename: Aldo J
authors.initials: AJ
authors.lastname: Peixoto
authors.forename: Mark
authors.initials: M
authors.lastname: Gorman
authors.forename: John L
authors.initials: JL
authors.lastname: Boice
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Bravata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications* / Q000401:mortality; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012306:Risk; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications* / Q000401:mortality; D013921:Thrombocytopenia / Q000150:complications* / Q000401:mortality