Clinical features of asthma with comorbid bronchiectasis: a systematic review and meta-analysis.

Objective: This meta-analysis aimed to systematically estimate the prevalence of comorbid bronchiectasis in patients with asthma and to summarize its clinical impact. Data sources: Embase, PubMed, and Cochrane Library electronic databases were searched to identify relevant studies published from inception until March 2020. Study Selection: Studies were included if bronchiectasis was identified by high-resolution computed tomography. Outcomes included prevalence of bronchiectasis and its association with demographic characteristics and indicators of asthma severity, including results of lung function tests and number of exacerbations. Results: Five observational studies with 839 patients were included. Overall, the mean prevalence of bronchiectasis in patients with asthma was 36.6% (307/839). Patients with comorbid bronchiectasis had lower forced expiratory volume (FEV1)/forced vital capacity (FVC) (MD: -2.71; 95% CI: -3.72 to -1.69) and more frequent exacerbations (MD: 0.68; 95% CI: 0.03 to 1.33) than those with asthma alone, there was no significant difference of sex, duration of asthma and serum levels of immunoglobulin(Ig)Es between asthmatic patients with or without bronchiectasis. Conclusion: The presence of bronchiectasis in patients with asthma was associated with greater asthma severity. There are important therapeutic implications of identifying bronchiectasis in asthmatic patients.