Cystic fibrosis (CF) is primarily characterised by bronchiectasis and trapped air on chest computed tomography (CT). The revised Cystic Fibrosis Questionnaire respiratory symptoms scale (CFQ-R RSS) measures health-related quality of life. To validate bronchiectasis, trapped air and CFQ-R RSS as outcome measures, we investigated correlations and predictive values for pulmonary exacerbations. CF patients (aged 6-20 years) underwent CT, CFQ-R RSS and 1-year follow-up. Bronchiectasis and trapped air were scored using the CF-CT scoring system. Correlation coefficients and backward multivariate modelling were used to identify predictors of pulmonary exacerbations. 40 children and 32 adolescents were included. CF-CT bronchiectasis (r = -0.38, p