Quality of Life and Airway Inflammation in Children With Asthma: Integrating Clinical and Functional Measures Through...

Asthma is one of the most prevalent chronic diseases in childhood and a major cause of respiratory morbidity, school absenteeism, and restrictions in physical activity. Although asthma control is commonly assessed using clinical and inflammatory markers, its functional impact on daily activities and participation is less frequently addressed. Fractional exhaled nitric oxide (FeNO) is a well-established biomarker of eosinophilic airway inflammation; however, its integration with quality-of-life measures within a biopsychosocial framework, such as the International Classification of Functioning, Disability and Health (ICF), remains limited. This study aimed to examine the associations between quality of life, airway inflammation, and functional status in children and adolescents with asthma using the ICF as a conceptual integrative framework.

This cross-sectional study included 112 children and adolescents with clinically diagnosed asthma receiving care at a pediatric respiratory physiotherapy clinic. Data collection comprised demographic and anthropometric variables, FeNO levels, and Pediatric Asthma Quality of Life Questionnaire (PAQLQ) scores. Clinical and patient-reported outcomes were conceptually linked to ICF categories related to body functions and activities and participation and expressed as functional impairment levels (0-4) for descriptive and comparative purposes. Descriptive analyses were performed, and participants were stratified according to FeNO levels (< 35 vs. ≥ 35 ppb). Group comparisons were conducted using Welch's t-test, with effect sizes estimated using Cohen's d (p < 0.05).

The sample had a mean age of 8.9 ± 2.7 years and a mean FeNO level of 47.1 ± 38.6 ppb. Overall PAQLQ scores indicated relatively preserved perceived quality of life across domains. ICF-based descriptive analysis indicated predominantly mild-to-moderate limitations in activity- and symptom-related domains and minimal emotional impairment, with a mean global ICF score of 1.5 ± 0.6. Participants with FeNO ≥ 35 ppb presented lower PAQLQ scores in symptoms, emotions, and activities, as well as higher global ICF scores, compared with those with FeNO < 35 ppb (all p ≤ 0.05). Effect sizes were large (Cohen's d ≥ 0.8).

Higher FeNO levels were associated with poorer quality-of-life scores and greater functional impairment. The conceptual integration of FeNO and PAQLQ findings within the ICF framework facilitated the interpretation of inflammatory status in relation to functional domains relevant to physiotherapy without implying causality. This approach supports a more comprehensive understanding of asthma-related functioning in children and adolescents.