title: The CHADS2 Components Are Associated with Stroke-Related In-hospital Mortality in Patients with Atrial Fibrillation.
abstract: BACKGROUND
  The CHADS2 score predicts stroke risk in patients with atrial fibrillation. Although strokes caused by atrial fibrillation carry the highest mortality when compared with other etiologies, it is not known whether the CHADS2 score predicts stroke-related mortality in patients with atrial fibrillation. We hypothesized that higher CHADS2 scores would be associated with higher stroke-related in-hospital mortality.
  
  
  METHODS
  Data were obtained from administrative claims data from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals between 2008 and 2011. Patients with atrial fibrillation and an admission for acute stroke were identified using appropriate International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification codes. Age and ICD-9 codes for hypertension, diabetes, congestive heart failure, and prior stroke were used to calculate the CHADS2 score of patients with atrial fibrillation. The primary outcome was in-hospital stroke mortality and the primary predictor was CHADS2 score. A multivariate logistic regression model adjusted for sex and race was used to determine the odds ratio (OR) and 95% confidence interval (CI) for the association between CHADS2 and mortality.
  
  
  RESULTS
  Between January 1, 2008, and December 31, 2011, 25,599 patients with atrial fibrillation were hospitalized with a stroke. The odds of in-hospital mortality was significantly higher with a CHADS2 score of 2 more versus less than 2 (OR, 1.15; 95% CI, 1.08-1.23); however, there was no dose-response association between the CHADS2 score and in-hospital mortality. Among the individual CHADS2 score items, factors associated with increased in-hospital mortality were congestive heart failure (OR, 1.61; 95% CI, 1.53-1.70), age 75 years or older (OR, 1.27; 95% CI, 1.19-1.35), and diabetes (OR, 1.24; 95% CI, 1.14-1.35).
  
  
  CONCLUSIONS
  Unlike prior studies, our studies show that the prestroke CHADS2 score is of limited use in predicting in-hospital mortality in ischemic stroke hospitalizations in patients with atrial fibrillation.
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY. Electronic address: shadiyaghi@yahoo.com.
authors.forename: Shadi
authors.initials: S
authors.lastname: Yaghi
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY.
authors.forename: Ayesha
authors.initials: A
authors.lastname: Sherzai
authors.affiliation: Department of Epidemiology and Public Health, Loma Linda University, Loma Linda, CA.
authors.forename: Markeith
authors.initials: M
authors.lastname: Pilot
authors.affiliation: Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA.
authors.forename: Dean
authors.initials: D
authors.lastname: Sherzai
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY; Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY.
authors.forename: Mitchell S V
authors.initials: MS
authors.lastname: Elkind
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications* / Q000235:genetics*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D038801:International Classification of Diseases; D016015:Logistic Models; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000209:etiology / Q000401:mortality
keywords: CHADS2 score; Stroke; atrial fibrillation; mortality; outcome