Unless CFTR modulators are highly effective, the introduction of CFTR (Cystic fibrosis transmembrane conductance regulator) modulators could lead to concomitant reduction or discontinuation of respiratory co-therapies in real-life. Such reduction/discontinuation of respiratory co-therapies could lead to an overall decrease of the effectiveness of CF care.

MODUCO study aims: 1) to compare the clinical effectiveness on lung function and pulmonary exacerbation of CFTR modulator during the year of initiation, according to level of co-therapy among CF patients; 2) to describe the nature and level of respiratory co-therapies (azithromycin, RhDNase, inhaled antibiotics) in the year before the initiation of CFTR modulator; 3) to describe the changes in respiratory co-therapies during the first and the second year following the initiation of CFTR modulator and compare between the two CFTR modulators; 4) to describe adherence to CFTR modulator during the first and the second year following its initiation; 5) to study the association between the nature of respiratory co-therapies and adherence to CFTR modulator during the first and the second year following its initiation.

A national population-based comparative effectiveness study will be conducted, based on retrospective analysis of clinical and prescription data of the French CF registry linked with the French national health data system (SNDS).

Inclusion Criteria:

• - CF patients aged 6 years and more,
• Treated at least 6 months by ivacaftor or lumacaftor/ivacaftor or elexacaftor/tezacaftor/ivacaftor,
• Included in the French CF registry,
• For whom probabilistic matching with the SNDS database has succeeded.

Exclusion Criteria:

• none

Exhaustive on the recruitment of the all french CF patients meeting with eligibility criteria.