Patterns and Non-Traditional Spirometric Indices in Pediatric Asthma: Toward Improved Disease Insights

Pediatric asthma is characterized by airway inflammation, hyperresponsiveness, and reversible obstruction. While spirometry is pivotal in asthma management, traditional spirometric indices may inadequately assess Small Airway Disease. This study aimed to explore the prevalence and characteristics of spirometric patterns in asthmatic children and evaluate non-traditional indices as tools for assessing airway dysfunction and asthma control.

This retrospective study included 162 asthmatic children aged 3-15 years who underwent spirometry. Asthma control was assessed using the Asthma Control Questionnaire (ACQ). Spirometric measurements included Forced Expiratory Volume in 1 s (FEV₁), Forced Vital Capacity (FVC), FEV₁/FVC ratio, Forced Expiratory Volumes at 0.5, 2, and 3 s (FEV_0.5, FEV₂, and FEV₃), and Forced Expiratory Time (FET). FEV_0.5/FVC, FEV₂/FVC, and FEV₃/FVC ratios were calculated. ROC curve analysis evaluated the diagnostic utility of spirometric indices for distinguishing controlled from uncontrolled asthma.

Preserved Ratio Impaired Spirometry (PRISm) was more prevalent (11.90%) than obstructive ventilatory defects (6%), reflecting the heterogeneity of asthma phenotypes. Uncontrolled asthma was associated with prolonged FET and lower FEV_0.5/FVC, FEV₁/FVC, FEV₂/FVC, and FEV₃/FVC ratios. Inverse correlations were observed between ACQ scores and non-traditional indices, particularly FEV_0.5/FVC (r = -0.572). FEV_0.5/FVC exhibited the highest diagnostic accuracy (AUC = 0.805, sensitivity = 89.9%, specificity = 67.7%), surpassing traditional indices.

Non-traditional spirometric indices, particularly FEV0.5/FVC, enhance the evaluation of airway dysfunction and asthma control in pediatric populations. Incorporating these indices into routine assessments offers a broader understanding of asthma phenotypes, supporting personalized management strategies.