2.1 Study design and population
In this observational study combining several existing trials, we included N2-MBW data from healthy children and children with CF from previously published trials and two ongoing cohort studies (Basel‐Bern Infant Lung Development (BILD) cohort 11and Swiss Cystic Fibrosis Infant Lung Development (SCILD) cohort12). The Ethics Committee of the Canton of Bern, Switzerland approved the study protocols (B2019‐01072, PB_2017‐02139, 2017-00279, 2017-00088) and parents gave written consent. We included MBW data from 275 study participants that were reported in previous studies and 28 participants from an ongoing trial (Table 1). Using the corrected results of these measurements, we evaluated the effect of the correction on MBW outcomes and consequently if clinimetric properties of LCI were affected.