Clinical performance of spirometry and respiratory oscillometry for prediction of severe exacerbations in schoolchildren with asthma

Objective: To determine the performance of spirometry and respiratory oscillometry (RO) in the prediction of severe asthma exacerbations (SAEs) in children.Methods: In a prospective study, 148 children (age 6-14 years) with asthma were assessed with RO, spirometry and a bronchodilator test. Based on the findings of spirometry and the broncho-dilator test, they were classified into 3 phenotypes: air trapping (AT), airflow limitation (AL) and normal. Twelve weeks later, they were re-evaluated in relation to the occurrence of SAEs. We analysed the performance of RO, spirometry and AT/AL phenotypes for prediction of SAEs by means of positive and negative likelihood ratios (LR+/LR-), ROC curves with the corresponding areas under the curve and a multivariate analysis adjusted for potential confounders.Results: During the followup, 7.4% of patients had SAEs, and there were differences between phenotypes (normal, 2.4%; AL, 17.9%; AT, 22.2%, P = .005). The best area under the curve corres-ponded to the forced expiratory flow between 25% and 75% of vital capacity (FEF25-75): 0.787; 95% confidence interval, 0.600-0.973. Other significant areas under the curve were those for the reactance area (AX), forced expiratory volume in the first second (FEV1), the post- broncho-dilator change in forced vital capacity (FVC), and the FEV1/FVC ratio. All of the variables had a low sensitivity for prediction of SAEs. The AT phenotype had the best specificity (93.8%; 95% confidence interval, 87.9-97.0), but LR+ and LR--were both significant only for the FEF25-75. In the multivariate analysis, only some spirometry parameters were significative for prediction of SAEs (AT phenotype, FEF25-75 and FEV1/FVC).Conclusions: Spirometry performed better than RO for prediction of SAEs in the medium term in schoolchildren with asthma.& COPY; 2023 Asociacion Espan & SIM;ola de Pediatri & PRIME;a. Published by Elsevier Espan & SIM;a, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).