Risk factors for FEV1 decline in European patients with CF: data from the European Cystic Fibrosis Society Patient Registry (ECFSPR)

AimTo examine the trajectory of forced expiratory volume in 1 s (FEV1) using data from the European Cystic Fibrosis (CF) Society Patient Registry collected from 2008 to 2016, hence the era before highly effective modulator therapy (HEMT). We evaluated risk factors for FEV1 decline.MethodsThe study population included patients with a confirmed diagnosis of CF recorded in the ECFPR (2008–2016). The evolution of FEV1% predicted with age (%FEV1), and the yearly change in %FEV1 were evaluated. Risk factors considered wereCFTRmutation class, gender, age at diagnosis, neonatal screening, meconium ileus, sweat chloride concentration at diagnosis, and country's income level.ResultsWe used 199,604 FEV1 recordings from 38,734 patients. The fastest decline was seen during puberty and in patients diagnosed before ten years. Males had a higher %FEV1 but a higher yearly %FEV1 loss between ages 15 and 25. We showed stabilization and even improvement in %FEV1 over age in adults with a class III mutation but a steady decline in patients homozygous for F508del or with both mutations of classes I/II. A faster decline in %FEV1 was found in patients from 'low-income' countries compared to a similar %FEV1 evolution in patients from middle- and high-income countries.ConclusionsThese longitudinal FEV1 data reflect the reality of CF across Europe in the era pre-HEMT and can serve as baseline for comparison with the post-HEMT era. The similar evolution in middle- and high-income countries underlines opportunities for low-income countries.