title: Predicting an asthma exacerbation in children 2 to 5 years of age.
abstract: BACKGROUND
  Asthma exacerbations in young children are prevalent. Identification of symptoms or other factors that are precursors of asthma exacerbations would be useful for early treatment and prevention.
  
  
  OBJECTIVE
  To determine whether diary symptoms and beta2-agonist use before an exacerbation could predict an asthma exacerbation in children 2 to 5 years of age.
  
  
  METHODS
  Post hoc analyses were conducted on data collected in a study of 689 patients 2 to 5 years of age with asthma symptoms, randomly assigned to montelukast, 4 mg, or placebo daily for 12 weeks. During the study, 196 patients had an exacerbation. Caregiver-reported information (daytime cough, breathing difficulties, limitation of activity, nighttime cough or awakening, daytime and nighttime beta2-agonist use) were analyzed using general estimating equations with an exchangeable within-subject log odds ratio regression structure to identify predictors of an exacerbation.
  
  
  RESULTS
  Average symptom scores and beta2-agonist use increased significantly before exacerbation but at different rates. A combination of daytime cough and wheeze and nighttime beta2-agonist use 1 day before the exacerbation was identified as strongly predictive of an exacerbation. These methods predicted 149 (66.8%) of the exacerbations with a very low false-positive rate of 14.2%.
  
  
  CONCLUSIONS
  No individual symptom was predictive of an imminent asthma exacerbation, but a combination of increased daytime cough, daytime wheeze, and nighttime beta2-agonist use 1 day before an asthma exacerbation was a strong predictor of an exacerbation in children.
authors.affiliation: Merck Research Laboratories, Rahway, New Jersey 07065, USA. swern_arlene@verizon.net
authors.forename: Arlene S
authors.initials: AS
authors.lastname: Swern
authors.forename: Carol A
authors.initials: CA
authors.lastname: Tozzi
authors.forename: Barbara
authors.initials: B
authors.lastname: Knorr
authors.forename: Hans
authors.initials: H
authors.lastname: Bisgaard
mesh_terms: D000085:Acetates / Q000008:administration & dosage / Q000627:therapeutic use; D000318:Adrenergic beta-Agonists / Q000008:administration & dosage* / Q000627:therapeutic use; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001249:Asthma / Q000503:physiopathology* / Q000517:prevention & control*; D002675:Child, Preschool; D003371:Cough / Q000503:physiopathology; D003521:Cyclopropanes; D004334:Drug Administration Schedule; D006801:Humans; D015999:Multivariate Analysis; D011379:Prognosis; D011804:Quinolines / Q000008:administration & dosage / Q000627:therapeutic use; D012075:Remission, Spontaneous; D012135:Respiratory Sounds / Q000503:physiopathology; D012720:Severity of Illness Index; D013440:Sulfides
chemical_list: D000085:Acetates; D000318:Adrenergic beta-Agonists; D018927:Anti-Asthmatic Agents; D003521:Cyclopropanes; D011804:Quinolines; D013440:Sulfides; C093875:montelukast