Predicting an asthma exacerbation in children 2 to 5 years of age

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. Objectives To determine whether diary symptoms and β 2 -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 β 2 -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 β 2 -agonist use increased significantly before exacerbation but at different rates. A combination of daytime cough and wheeze and nighttime β 2 -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 β 2 -agonist use 1 day before an asthma exacerbation was a strong predictor of an exacerbation in children.