title: Validity of the Seattle Heart Failure Model for prognosis in a population at low coronary heart disease risk.
abstract: OBJECTIVE
  Validation of the Seattle Heart Failure Model (SHFM) for predicting the risk of death in a population different than the derivation cohort.
  
  
  METHODS
  In a retrospective analysis of a cohort of chronic heart failure patients with left ventricular systolic dysfunction, consecutively referred between 2000 and 2011, we computed the score, according to characteristics at referral. We compared the observed risk of death with that predicted by the model, using receiver operating characteristic (ROC) curves to assess discrimination and a goodness-of-fit test for the comparison of predicted and observed risks.
  
  
  RESULTS
  In 565 patients, 68.5% were men, the median age was 70 years, 46.0% had ischemic cause, 89.7% moderate-severe left ventricular systolic dysfunction and 61.2% New York Heart Association class II. The risk of death increased progressively with the model's score, with an area under the ROC curve between 0.69 and 0.72 when considering different follow-up periods. The model underestimated the risk of death (observed vs. predicted: 12.2 vs. 10.4%, P < 0.001; 28.1 vs. 25.1%, P < 0.001; and 43.4 vs. 35.7%, P < 0.001 at 1, 3 and 5 years, respectively). Accurate predictions, with nonsignificant differences between observed and predicted risks in a goodness-of-fit test, were obtained after recalibration.
  
  
  CONCLUSIONS
  In this study, the SHFM substantially underestimated the absolute risk of death in ambulatory chronic heart failure patients, mostly nonischemic and elderly. After adjustment for sample-specific circumstances, the recalibrated model demonstrated to be credible in clinical practice and may provide useful information to physicians.
authors.affiliation: aInstitute of Public Health of the University of Porto bDepartment of Clinical Epidemiology, Predictive Medicine and Public Health, University of Porto Medical School cHeart Failure Clinic, Department of Internal Medicine, Centro Hospitalar de São João dCardiovascular Research and Development Unit, University of Porto Medical School, Porto, Portugal.
authors.forename: Olga
authors.initials: O
authors.lastname: Laszczyńska
authors.forename: Milton
authors.initials: M
authors.lastname: Severo
authors.forename: Fernando
authors.initials: F
authors.lastname: Friões
authors.forename: Patrícia
authors.initials: P
authors.lastname: Lourenço
authors.forename: Sérgio
authors.initials: S
authors.lastname: Silva
authors.forename: Paulo
authors.initials: P
authors.lastname: Bettencourt
authors.forename: Nuno
authors.initials: N
authors.lastname: Lunet
authors.forename: Ana
authors.initials: A
authors.lastname: Azevedo
mesh_terms: D000368:Aged; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015233:Models, Statistical; D011174:Portugal / Q000453:epidemiology; D011379:Prognosis; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology