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

Area of Science:

• Pediatric Pulmonology
• Respiratory Physiology

Background:

• The Global Lung Initiative (GLI) has established new reference values for lung function, recommended by major health organizations.
• Previous reference values, such as the Zapletal values, have been widely used in clinical practice.

Purpose of the Study:

• To compare FEV1 and FEV1/FVC values in a German and Austrian pediatric cohort using both GLI and Zapletal reference values.
• To assess the impact of the new GLI reference values on the interpretation of lung function in children with respiratory conditions.

Main Methods:

• Analysis of FEV1 and FEV1/FVC data from 215 Caucasian children aged 5-17 years.
• Comparison of lung function parameters obtained using GLI reference values versus Zapletal reference values.

Main Results:

• FEV1 values were significantly lower when using GLI reference values compared to Zapletal values (median 96.9% predicted vs. 100.6% predicted).
• A notable proportion of pediatric patients with cystic fibrosis (36%) showed abnormal FEV1 (z-score <1645) with GLI values, compared to 24% with Zapletal values (<80% predicted).
• In pediatric asthma patients, 5% had abnormal FEV1 (z-score <1645) with GLI values, versus 2% with Zapletal values (<80% predicted).

Conclusions:

• The differences between GLI and Zapletal reference values are substantial in pediatric patients, particularly those with asthma and cystic fibrosis.
• The adoption of GLI reference values may lead to a different classification of lung function abnormalities in children.