title: Asthma score: predictive ability and risk factors.
abstract: BACKGROUND
  Definition of asthma as a continuous score is a promising tool for population studies that has not yet been fully evaluated.
  
  
  OBJECTIVE
  We assessed (i) the predictive ability of an asthma score against the occurrence of different asthma-related outcomes and (ii) the risk factors identified when using an asthma score.
  
  
  METHODS
  The European Community Respiratory Health Study II included subjects from the general population randomly studied during 1991-1993 who were followed up in the years 1998-2001, from 29 centres in 14 countries. A total of 8956 subjects were included. The asthma score consisted of a simple sum of the positive answers to five respiratory symptoms.
  
  
  RESULTS
  Asthma score at baseline showed a linear relationship with incidence of asthma, the occurrence of asthma attacks, use of asthma medication and bronchial reactivity at the end of the follow-up. Asthma score at the end of follow-up was associated with known risk factors at baseline such as IgE to grass, rhinitis or body mass index, in addition to passive smoking in men [average score ratio (RR) = 1.30; 95% confidence interval (CI) 1.09-1.50] or changes in body mass index (RR = 1.27; 95% CI 1.05-1.27, per each kg/m(2)).
  
  
  CONCLUSIONS
  The asthma score had good predictive ability against outcomes related with asthma and also good ability to detect risk factors. This encourages the use of the score as a measure of asthma in epidemiological studies on aetiology of asthma.
authors.affiliation: Medical Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sunyer
authors.forename: J
authors.initials: J
authors.lastname: Pekkanen
authors.forename: R
authors.initials: R
authors.lastname: Garcia-Esteban
authors.forename: C
authors.initials: C
authors.lastname: Svanes
authors.forename: N
authors.initials: N
authors.lastname: Künzli
authors.forename: C
authors.initials: C
authors.lastname: Janson
authors.forename: R
authors.initials: R
authors.lastname: de Marco
authors.forename: J M
authors.initials: JM
authors.lastname: Antó
authors.forename: P
authors.initials: P
authors.lastname: Burney
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D012720:Severity of Illness Index