Eligibility criteria {10}
CF, PEx
All children and adults with a confirmed diagnosis of CF are eligible for inclusion in the PEx cohort, excluding those with a history of lung transplantation. Additional eligibility criteria (typically exclusion criteria) may apply to cohort-nested sub-studies, and these will be detailed in their relevant subprotocols or appendices. Co-enrolment of participants in other studies is permitted, whether they are formally nested in the PEx cohort or not, including interventional trials, except when there is a clear threat to the validity of either study, or where co-enrolment would materially influence the risk to participants.