There is no gold-standard for diagnosing asthma in children. This study aimed to investigate the real-life impact on disease progression and adherence by applying diagnostic criteria from international guidelines. One hundred and fifteen children with pediatrician-diagnosed asthma aged 5-17 years were followed for 5 years in a pediatric asthma clinic. In a diagnostic 2-year period we evaluated if children had a "guideline-confirmed diagnosis" or not. A guideline-confirmed diagnosis required two of five criteria, (1) FEV1%-predicted < 80%, (2) FEV1/FVC-ratio < 80%, (3) Bronchodilator response ≥ 12% increase in FEV1, (4) FeNO ≥ 25ppb or (5) Positive exercise or mannitol test. In a subsequent 3-year follow-up period we assessed lung function development and acute asthma events. Sixty three percent of the children had a guideline-confirmed diagnosis. All children had improvements in lung function, with higher increase in FEV1%-predicted per year for children with a guideline-confirmed diagnosis versus without (beta-coefficient: 5.4 (4.5-6.3) vs. 3.7 (2.5-4.9), p = 0.026). Children with versus without a guideline-confirmed diagnosis had higher risk of acute asthma events (IRR: 4.7 (1.6-21.0), p = 0.017), hospitalization (10 vs. 1 event, p = 0.024) and oral corticosteroid treatment (OR: 6.0 (1.1-112.7), p = 0.04). Adherence was not associated with a guideline-confirmed diagnosis and time to guideline-confirmed diagnosis was not associated with disease progression. Objective tests are important for diagnosing asthma, as children with ≥ 2 positive tests exhibited more acute events and greater benefit from treatment. However, improved lung function and acute events also occurred in children with < 2 positive tests, emphasizing the importance of a comprehensive diagnostic approach for pediatric asthma.
Hauerslev et al. (Fri,) studied this question.