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

Abstract

Introduction: 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.

Objectives: 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.

Methods: 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.

Results: 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).

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

Keywords: Children; Espirometría; Global Lung Function Initiative; Niños; Preescolares; Preschool children; Reference values; Spirometry; Valores de referencia.