To examine the association between the National Asthma Education and Prevention Program (NAEPP) severity levels and other measures of burden of disease in children with acute asthma.

A cross-sectional study in 750 children less than 18 years of age with a physician diagnosis of asthma and treated in an emergency department (ED) for an acute asthma exacerbation. Patients were assigned to one of the 4 levels of severity (mild intermittent [MI], or mild [MP], moderate [MDP] or severe [SP] persistent) in one of two ways: by report of symptom frequency alone (standard method), or according to symptom frequency and reported controller medication use (modified method). Parents also completed an asthma-specific quality of life score, the Integrated Therapeutics Group Short Form (ITGSF), and reported on the number of ED visits and hospital admissions for asthma over the prior 12 months. Differences between severity groups were compared with ANOVA, and the proportion of variance explained (r2) was calculated.

Using the standard classification, 55% were MI, 21% MP, 14% MDP, and 10% SP. 22% of those with intermittent asthma by symptoms alone were reclassified as persistent asthma when controller medications were accounted for. Using either method of classification, the mean ITG scores decreased significantly with each increasing level of severity (r2=0.23-0.25). There was also a significant but modest association between severity level and mean number of ED visits (r2=0.11) and hospitalizations (r2=0.07).

NAEPP severity classification alone provides an incomplete picture of the burden of disease in children with asthma.