Subjects

Consecutive patients with symptoms of chronic cough, sputum production and/or hemoptysis, aged 18-75 years, remaining clinically stable for 4 weeks, were recruited from respiratory out-patient clinics between September 2012 and July 2013. Bronchiectasis was confirmed by study investigators via chest high-resolution computed tomography (HRCT) review. Those with malignancy, upper respiratory tract infection or antibiotic use within 4 weeks were excluded. To minimize the potential bias to BDR, we also excluded patients with physician-diagnosed asthma and COPD.

This study was approved by the Ethics Committee of The First Affiliated Hospital of Guangzhou Medical University. All patients signed informed consent.