Introduction. Recently published multi-ethnic spirometry reference equations for Caucasian subjects from 3 to 95 years (Quanjer et al Eur Respir J 2012) provide a worldwide standard for interpreting spirometric test results. Objective . To assess how well the GLI equations fit spirometry data from "healthy" Spanish school age children, in order to verify the appropriateness of this reference for clinical use in this population. Methods. Two spirometric measurements (n=722/603) were obtained, according to ERS/ATS guidelines, at 7 randomly selected schools from Barcelona (Spain) in children aged 7 to 14.9 years, with a mean (SD) interval between the two tests of 54.3 days (35.3) (range 10 – 135 days). Z-scores were calculated for the spirometry outcomes based on the GLI equations. If there was no offset between the reference and test populations, the mean (SD) z-scores of the test population would be 0 (1). A difference of ≥ 0.5 z-score was considered to be clinically significant. Results. Of 722 children recruited, 662 were White and 442 (66.8%) fulfilled our criteria as 'healthy'. Of these 71.9% performed technically acceptable and reproducible manoeuvres. FVC FEV1 FEV1/FVC FEF25-75 N (1st / 2nd test) 300 / 274 318 / 288 300 / 274 300 / 274 First test Z-score; mean (SD) 0,74 (0.98) 0,66 (1.01) -0,18 (0.88) -0,11 (1.01) Second test Z-score; mean (SD) 0,51 (0.94) 0,41 (0.99) -0,21 (0.89) -0,27 (0.99) Conclusions . The finding of values outside 0.5 z-scores of GLI predicted values suggests poor fit with GLI equations. Reasons for these discrepancies should be investigated before applying the GLI equations in Spanish school age children.
Iglesias et al. (Mon,) studied this question.