Collating data from major European population studies - The CADSET (Chronic airway disease early stratification) clinical research collaboration

Background: European population cohorts continue to expand our understanding of chronic airways disease and inter-study collaboration may help address the inevitable limitations of study size, duration, era and geography. Towards this aim, CADSET has collated data from ten major general population European cohorts: Asklepios; Copenhagen City Heart Study; Copenhagen General Population Study; ECRHS; HUNT; LEAD; Lifelines, OLIN, Rotterdam Study and WSAS. We included males and females aged 20 to 95 years with baseline demographic and spirometry data. Results: Data from 262,829 individuals (44% male) from multiple European countries provided good coverage across all adult ages (Fig.1A). Recruitment occurred in every year from 1976 through 2020. 23% were current-smokers and 42% were never-smokers, a pattern varying with advancing age (Fig.1B). The prevalence of airflow limitation varied according to whether lower limit of normal (LLN) or <0.70 thresholds were applied, increasing with age if the latter was used (Fig.1C). Interpretation: These results fit with previous reports, however the size, geographical reach and span of recruitment provided by this collaboration provides a unique opportunity to explore chronic airways disease development. Together, we are now pursuing research questions previously beyond the scope of individual cohort studies.