Latent Class Analysis of School-Age Children at Risk for Asthma Exacerbation

BACKGROUND: Factors responsible for asthma exacerbations in children are complex and may differ from those that drive asthma severity. OBJECTIVE: To identify latent classes of children at risk for asthma exacerbation and determine whether latent class assignment is useful in the prediction of future exacerbation. METHODS: Latent class analysis was performed on 513 children aged 6 to 17 years at risk for asthma exacerbation, with 31 variables encompassing demographics, medical history, treatment, symptoms, lung function, sensitization, and type 2 inflammation. Primary and secondary outcomes included exacerbation occurrence by 12 months and time to first exacerbation, respectively. RESULTS: Four latent classes were identified with differing demographic features, sensitization and type 2 inflammatory markers, prior exacerbation severity and health care utilization, and lung function. Exacerbations occurred in 22.4% of class 1 ("lesser sensitization with normal lung function"), 27.9% of class 2 ("lesser sensitization with prior severe exacerbation and normal lung function"), 45.3% of class 3 ("multiple sensitization with reversible airflow limitation"), and 64.3% of class 4 ("multiple sensitization with partially reversible airflow limitation") (P <.001). Time to exacerbation also followed similar trends and was shortest in the latent classes with multiple sensitization and airflow limitation (P <.001). Outcomes were driven largely by children with exacerbation-prone asthma (defined as >= 3 exacerbations in the prior year), who were present in each class but most strongly represented in classes 3 and 4. CONCLUSIONS: Children at risk for asthma exacerbation are a heterogeneous group. Sensitization, prior exacerbation severity, and lung function variables may be particularly useful in identifying children at greatest risk for future exacerbation. (C) 2020 American Academy of Allergy, Asthma & Immunology.