Characteristics of exacerbators in the US Bronchiectasis and NTM Research Registry: a cross-sectional study

Exacerbations of non-cystic fibrosis bronchiectasis (bronchiectasis) are associated with reduced health-related quality of life and increased mortality, likelihood of hospitalisation, and lung function decline. This study investigated patient clinical characteristics associated with exacerbation frequency.A cross-sectional cohort study of patients ≥18 years with bronchiectasis enrolled in the US Bronchiectasis and Nontuberculous Mycobacteria (NTM) Research Registry (BRR) September 2008–March 2020. Patients were stratified by exacerbation frequency in their 2 years before enrollment. Patient demographics, respiratory symptoms, healthcare resource utilisation, microbiology, modified bronchiectasis severity index (mBSI), and select comorbidities were collected at enrollment. Patient characteristics associated with exacerbation frequency were assessed using a negative binomial model.The study included 2950 patients (mean age 65.6 years; 79.1% female). Frequency of moderate to severe airway obstruction (forced expiratory volume in 1 s [FEV1] % predicted <50%; most recent measure) was 15.9%, 17.8%, and 24.6% in patients with 1, 2, and ≥3 exacerbationsversus8.9% in patients with 0 exacerbations; severe disease (mBSI) was 27.8%, 24.2%, and 51.1%versus13.2%; respiratory hospitalisation was 24.5%, 33.0%, and 36.5%versus4.1%; andPseudomonas aeruginosainfection was 18.8%, 23.4%, and 35.2%versus11.9%. In multivariable model analysis, respiratory hospitalisation, cough, haemoptysis,P. aeruginosa, younger age, lower FEV1% predicted, asthma, and gastroesophageal reflux disease were associated with more exacerbations.These findings demonstrate a high disease burden, including increased respiratory symptoms, healthcare resource utilisation, andP. aeruginosainfection in patients with bronchiectasis and multiple exacerbations.