Thoracic excursion measurement in children with cystic fibrosis

Measurement of thoracic excursion (TEM) during maximal ventilation is part of the physiotherapy assessment in children with cystic fibrosis (CF). The purpose of our study was to examine the reliability of TEM and its relation with pulmonary function. Thoracic excursions were measured using a measuring tape. Thirty children participated in an intra-observer and inter-observer reliability study. Reliability was determined by calculating the typical error in repeated measurement, limits of agreement and correlation coefficients. Cross-sectional data from the annual check-ups were used to measure the relation between TEM and pulmonary function. In the intra-observer reliability study the typical error was 0.31 cm, the limits of agreement were +/-0.86 cm. Pearson's r and ICC were 0.96 and 0.95, respectively. In the inter-observer reliability study these values were 0.56 cm, +/-1.55 cm, 0.85 and 0.85, respectively. TEM correlated significantly with height (0.31, P <0.001), FVC (0.44, P <0.001), FEV1 (0.41, P <0.001) and TLC (0.19, P <0.05), and there was a significant inverse correlation with RV%TLC (-0.45, P <0.001). TEM is a reliable assessment tool. Thoracic excursion is significantly, although moderately correlated with pulmonary function