Implications of removing race from spirometry reference equations in children with asthma

The Global Lung Initiative (GLI) recently developed a race-neutral reference equation in 2022 (GLI-2022); however, the implications of its use in children with asthma, especially Latino children, have not been extensively studied.

To assess the difference in spirometry results, asthma severity, and airway obstruction classification for African American (AA), Latino, and White children with asthma after implementing GLI-2022.

This retrospective cross-sectional study evaluated the first spirometry performed by children with asthma aged 5 to 17 years between January 1, 2018, and December 31, 2023. z-Scores and percent-predicted (pp) values for forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and FEV₁/FVC were calculated using GLI-2022 and race-adjusted GLI-2012 equations.

A total of 7138 children (3543 AA, 2795 White, and 800 Latino) were included (median age = 10.3 years). FEV₁ z-score median difference was -0.872, -0.360, and +0.267 in AA, Latino, and White children, respectively (P < .0001) after implementing GLI-2022. FVC z-scores, ppFEV₁, and ppFVC values demonstrated similar patterns. Adopting GLI-2022 worsened asthma severity (based on ppFEV₁) and degree of airway obstruction (based on FEV₁ z-score) classifications in AA children, improved them in White children, and did not affect Latino children.

Implementing GLI-2022 affected asthma severity and airway obstruction classifications and resulted in a lower FVC and FEV₁ in AA and Latino children and greater values in White children. Using GLI-2022 may uncover more cases of underdiagnosed asthma in AA and Latino children, which may contribute to alleviating disparate asthma outcomes.