Methods
We included children with cystic fibrosis followed at the Hacettepe University Pediatric Pulmonology Department. The study was performed in accordance with the protocol approved by the local ethical committee (Hacettepe University, GO 15/811), and all parents/guardians gave written informed consent.
We carried out a self-designed questionnaire survey concerning demographic factors [age at CF diagnosis, Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mutation results years of follow up, history of allergic diseases and DHRs, detailed data about chronically used medications (the onset and duration of use, administration route)] and reviewed medical records to note the hospitalizations due to lower respiratory tract infections and/or number of parenteral AB used within last year, average annual use of oral antibiotics, complications related with CF and chronic colonizations (Pseudomonas aeruginosa, Staphylococcus aureus ). In case of history or new occurrence of any suspicious DHR, the patients were evaluated by the pediatric allergy department.