Spirometry thresholds for clinical trial eligibility: time for urgent re-evaluation.

ABSTRACT: A common eligibility criterion in respiratory clinical trials is a per cent-predicted forced expiratory volume in 1 second (ppFEV₁) between 40% and 90%, using the ethnicity-dependent Global Lung Function Initiative (GLI)-2012 spirometry reference equations. International societies now endorse the newer 'race-neutral' GLI-Global equations. We quantify the impact on trial eligibility of switching from GLI-2012 to GLI-Global for the UK Cystic Fibrosis Registry (n=8182). In a future trial with a maximum eligibility threshold of ppFEV₁=90%, the changes in ppFEV₁ would lead to over 700 people becoming newly ineligible. Urgent review of fixed ppFEV₁ thresholds is required, with an initial recommendation to widen the range to 30-95% ppFEV₁ whe

SUBMITTER: Bokobza I 

PROVIDER: S-EPMC12573418 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature