title: Added predictive ability of the CHA2DS2VASc risk score for stroke and death in patients with atrial fibrillation: the prospective Danish Diet, Cancer, and Health cohort study.
abstract: BACKGROUND
  The objective of this study was to evaluate the added predictive ability of the CHA(2)DS(2)VASc prediction rule for stroke and death in a nonanticoagulated population of patients with atrial fibrillation.
  
  
  RESULTS
  We included 1603 nonanticoagulated patients with incident atrial fibrillation from a Danish prospective cohort study of 57 053 middle-aged men and women. The Net Reclassification Improvement was calculated as a measure to estimate any overall improvement in reclassification with the CHA(2)DS(2)VASc sore as an alternative to the CHADS(2) score. After 1-year follow-up, crude incidence rates were 3.4 per 100 person-years for stroke and 13.6 for death. After a mean follow-up of 5.4 years (± 3.7 years), the crude incidence rates for stroke and death were 1.9 and 5.6, respectively. During the entire observation period, the c-statistics and negative predictive values were similar for both risk scores. The Net Reclassification Improvement analysis showed that 1 of 10 reclassified atrial fibrillation patients would have been upgraded correctly using the CHA(2)DS(2)VASc score.
  
  
  CONCLUSIONS
  Both the CHADS(2) as well as the CHA(2)DS(2)VASc risk score can exclude a large proportion of patients from having high risk of stroke or death. However, using the CHA(2)DS(2)VASc risk score, fewer patients will fulfill the criterion for low risk (and are truly low risk for thromboembolism). For every 10 extra patients transferred to the treatment group at 5 years, using the CHA(2)DS(2)VASc risk score, 1 patient would have had a stroke that might have been avoided with effective treatment.
authors.affiliation: Department of Cardiology, Aalborg AF Study Group, Cardiovascular Research Centre, Aarhus University Hospital, Aalborg, Denmark. tobl@rn.dk
authors.forename: Torben Bjerregaard
authors.initials: TB
authors.lastname: Larsen
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: Flemming
authors.initials: F
authors.lastname: Skjøth
authors.forename: Karen Margrete
authors.initials: KM
authors.lastname: Due
authors.forename: Kim
authors.initials: K
authors.lastname: Overvad
authors.forename: Lars
authors.initials: L
authors.lastname: Hvilsted Rasmussen
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology* / Q000401:mortality; D003718:Denmark / Q000453:epidemiology; D004032:Diet / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D013997:Time Factors
chemical_list: D000925:Anticoagulants