title: Performance of the CHARGE-AF risk model for incident atrial fibrillation in the EPIC Norfolk cohort.
abstract: BACKGROUND
  Identification of individuals at risk for developing atrial fibrillation (AF) will help to target screening and preventive interventions. We aimed to validate the CHARGE-AF model (including variables age, race, height, weight, blood pressure, smoking, antihypertensive medication, diabetes, myocardial infarction and heart failure) for prediction of five-year incident AF in a representative European population with a wide age range.
  
  
  RESULTS
  The CHARGE-AF model was calculated in 24,020 participants of the population-based EPIC Norfolk study with 236 cases of hospitalization with diagnosis of AF within five years. The model showed good discrimination (c-statistic 0.81, 95% confidence interval (CI) 0.75-0.85), but weak calibration (Chi(2)-statistic 142) with an almost two-fold overestimation of AF incidence. A recalibration to characteristics of the European Prospective Investigation into Cancer and Nutrition (EPIC) Norfolk cohort improved calibration considerably (Chi(2)-statistic 13.3), with acceptable discrimination in participants both >65 and ≤65 years of age (c-statistics 0.70, 95% CI 0.61-0.77 and 0.83, 95% CI 0.74-0.88). The recalibrated model also showed good discrimination in participants free of cardiovascular disease (c-statistics 0.80, 95% CI 0.75-0.84). Categories of predicted risk (<2.5%, 2.5-5% or >5%) showed good concordance with observed five-year AF incidence of 0.62%, 3.49% and 8.74% (log rank test p < 0.001), respectively.
  
  
  CONCLUSIONS
  A recalibration of the CHARGE-AF model is necessary for accurate predictions of five-year risk of AF in the EPIC Norfolk population. The recalibrated model showed good discrimination across a wide age range and in individuals free of cardiovascular disease, and hence is broadly applicable in primary care to identify people at risk for development of AF.
authors: Department III of Internal Medicine, Heart Centre of the University of Cologne, Germany roman.pfister@uk-koeln.de.
authors: Roman
authors: R
authors: Pfister
authors: Department III of Internal Medicine, Heart Centre of the University of Cologne, Germany.
authors: Johannes
authors: J
authors: Brägelmann
authors: Department III of Internal Medicine, Heart Centre of the University of Cologne, Germany.
authors: Guido
authors: G
authors: Michels
authors: Medical Research Council Epidemiology Unit, Institute of Metabolic Science, University of Cambridge, UK.
authors: Nick J
authors: NJ
authors: Wareham
authors: Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, UK.
authors: Robert
authors: R
authors: Luben
authors: Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, UK.
authors: Kay-Tee
authors: KT
authors: Khaw
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000208:ethnology; D016009:Chi-Square Distribution; D015897:Comorbidity; D016002:Discriminant Analysis; D004739:England / Q000453:epidemiology; D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011320:Primary Health Care; D016016:Proportional Hazards Models; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013997:Time Factors; D044465:White People
keywords: Atrial fibrillation; risk prediction; score