Longitudinal changes in time domain spirogram indices and their variability

摘要: The purpose of this study was to describe longitudinal changes in time domain spirogram indices and their variability. We therefore measured forced expiratory spirograms 326 middle-aged male employees two asbestos-using factories four times over 5 yrs. From the original sample 326, 225 healthy subjects, who provided reliable results for three or more surveys, were selected analysis. mean standard deviation transit log-transformed values (MTT, STT, ln(MTT), ln(STT), respectively), as well estimated constant distribution (Mu Sigma, respectively) analysed using a model. longitudinally annual increase MTT, ln(STT) about larger than cross-sectional estimate, whilst they comparable Mu Sigma. A highly significant contribution between-subject variability found all indices. This particularly remarkable components. eight error variance Mu, MTT ln(MTT). conclude that data should not be compared with reference values, magnitude these repeated measurements will rather less counterpart reported previously.