Symptom Clusters in Children With Exacerbation-prone Asthma

Asthma symptom control is suboptimal in the majority of children in the United States, despite widespread availability of asthma controller medications and standardized treatment guidelines. While deaths from asthma have declined, 53.7% of children with asthma continue to experience an exacerbation each year and the associated public health burden is substantial.

While the factors responsible for poor asthma symptom control are complex and include limited access to care, poor adherence to preventative asthma medications, and exposures to environmental allergens and irritants such as tobacco smoke, it is also recognized that children with exacerbation-prone asthma are a heterogeneous group with differing clinical outcomes and longitudinal disease trajectories. Symptoms (defined as subjective sensations) can also be quite varied within and among affected children. Whereas some children have persistent, troublesome respiratory symptoms, others have respiratory symptoms only with upper respiratory infections. Mental health symptoms and social health symptoms have been inadequately characterized in this population, but some children with asthma also report depression and anxiety and impaired family functioning and relationships that may further worsen asthma outcomes. However, prior studies are limited by a narrow focus on individual symptoms in isolation. To date, there has been no attempt to identify symptom clusters (defined as two or more concurrent symptoms independent of other clusters) in children with exacerbation-prone asthma.

Poor understanding of symptom clusters is a major shortcoming in asthma symptom science. In other chronic disorders such as cancer, compared with a single symptom, symptom clusters of pain, fatigue, sleep disturbance and mood disturbance significantly worsen patient-reported outcomes of functional status and quality of life. There is also emerging evidence that interventions for one symptom within a cluster (i.e., cognitive-behavioral therapy for pain) reduce the severity of other symptoms within that cluster (i.e., fatigue and sleep disturbance). Because children with exacerbation-prone asthma rarely report a single symptom, greater knowledge of the assessment (and ultimately management) of symptom clusters in these children has the potential to significantly improve individualized treatment and clinical outcomes.

The researchers here propose a 48-week cohort study (N=173) to test the overarching hypothesis that symptom clusters and their associated inflammatory and metabolic pathways predict corticosteroid treatment responsiveness (primary objective outcome) and quality of life (patient-reported secondary outcome) in children 8-17 years with exacerbation-prone asthma.