Validation of Global Lung Function Initiative and All Ages Reference Equations for Forced Spirometry in Healthy...

Recent publication of multi-ethnic spirometry reference equations for subjects aged from 3-95 years aim to avoid age-related discontinuities and provide a worldwide standard for interpreting spirometric test results.

To assess the agreement of the Global Lung Function Initiative (GLI-2012) and All ages (FEV_0.5) reference equations with the Spanish preschool lung function data. To verify the appropriateness of these reference values for clinical use in Spanish preschool children.

Spirometric measurements were obtained from children aged 3 to 6 years attending 10 randomly selected schools in Barcelona (Spain). Stanojevic's quality control criteria were applied. Z-scores were calculated for the spirometry outcomes based on the GLI equations. If the z-score (mean) of each parameter was close to 0, with a maximum variance of ± 0.5 from the mean and a standard deviation of 1, the GLI-2012 equations would be applicable in our population.

Of 543 children recruited, 405 (74.6%) were 'healthy', and of these, 380 were Caucasians. Of these 380, 81.6% (169 females, 141 males) performed technically acceptable and reproducible maneuvers to assess FEVt, and 69.5% achieved a clear end-expiratory plateau. Z-scores for FVC, FEV₁, FEV₁/FVC, FEV_0.75, FEV_0.75/FVC, FEV_0.5, FEF₇₅ and FEF_25-75 all fell within ± 0.5, except for FEV₁/FVC (0.53 z-scores).

GLI equations are appropriate for Spanish preschool children. These data provide further evidence to support widespread application of the GLI reference equations.