[New international reference values for spirometry: implications for clinical issues using a comparative analysis of a paediatric population].

Background: The new lung function reference values of the global lung initiative (GLI) are recommended by most health societies. The aim of this study was to analyze FEV1- and FEV1/FVC-values from a German and Austrian patient group applying old and new reference values.

Results: A total of 215 Caucasian children (aged 5-17 years) were included. FEV1-values were significantly lower applying GLI reference values compared to Zapletal values (median 96.9 % pred. (87.3-105.2) versus 100.6 % pred. (quartile 91.5-111.4), p = 0.000), the median difference was 4.9 % (range -12.9 to 27.5) % pred. Differences correlated significantly with age and FEV1 in % predicted (Zapletal), p = 0.000 17/70 (24 %) patients with cystic fibrosis had FEV1-values <80% pred. applying Zapletal, in 25 (36 %) patients FEV1 was abnormal (z-score <1645) using GLI values; 3/145 asthmatics (2 %) had FEV1-Werte <80 % d.S. (Zapletal), 7/145 (5 %) z-scores <1645 (GLI).

Conclusion: Differences between GLI-and Zapletal-reference values were considerable in pediatric asthma and CF-patients.