Impulse oscillometry in preschool children with persistent asthma can
predict spirometry at school age.
Background: Lung function in children with persistent asthma
may be impaired during preschool and school ages. The aim of this study
was to describe if some preschool IOS parameters are related to
spirometry alterations on reaching school age. Methods: 66
children under six years old diagnosed with persistent asthma were
studied prospectively with IOS during their preschool years and
spirometry at school age. Results: The mean age was 4.9 years
at the first evaluation and 7.9 years at the second evaluation, and
59.1% were male. During preschool, R5, Fres, AX, and D5-20 were found
to have diagnostic accuracy (AUC>0.7) for predicting
altered spirometry during school age (defined as FEV1 and/or FEV/FVC
and/or FVC values below the lower limit of normality according to
Quanjer predictive values). AX, D5-20, and R5 had the best LR+ to
increase the probability of altered spirometry (50, 10, and 7.1,
respectively). R5 was the best IOS parameter for discriminating
bronchodilator response (BDR) in schoolchildren (AUC=0.7, LR+ = 3.7).
Abnormal IOS increases the risk of having abnormal spirometry (RR=12.7,
p= 0.002). This risk is even higher in atopic patients (RR= 21,
p=0.003). Conclusion: The findings of this study indicate that
some IOS parameters between 3 and 5 years of age are useful for
predicting abnormal spirometry and BDR at school age.