Acute respiratory events in patients with bronchiectasis-COPD overlap syndrome: A population-based cohort study.

BACKGROUND: The clinical phenotypes of chronic obstructive pulmonary disease (COPD) are related to various outcomes. We investigated the risk of acute respiratory events in patients with bronchiectasis-COPD overlap syndrome (BCOS) in Taiwan.

METHODS: We included 3955 patients who received diagnoses of COPD and bronchiectasis from 2000 to 2007 from the Taiwan Longitudinal Health Insurance Database in the BCOS cohort. In the comparison cohort, we included patients with COPD but without bronchiectasis at a ratio of 4:1, frequency matched by age, sex, and index year with each patient with BCOS. We followed both cohorts for 5 years to investigate the incidence and risk of acute respiratory events in the BCOS cohort relative to the comparison cohort, the incidence rate ratios (IRRs) and corresponding 95% confidence intervals (CIs) were determined using Poisson regression models.

RESULTS: The BCOS cohort experienced more episodes of acute respiratory events than did the comparison cohort (16.4 vs 5.52 per 100 person-y). After adjustment for potential covariates, the BCOS cohort had a 2.20-fold higher risk of pneumonia (adjusted IRR = 2.20, 95% CI = 2.06-2.34), a 3.88-fold higher risk of acute exacerbation (adjusted IRR = 3.88,95% CI = 3.64-4.13), a 1.74-fold higher risk of acute respiratory failure (adjusted IRR = 1.74,95% CI = 1.47-2.06), and a 1.99-fold higher risk of cardiopulmonary arrest (adjusted IRR = 1.99,95% CI = 1.81-2.20) than did the comparison cohort.

CONCLUSION: The patients with BCOS had a higher risk of acute respiratory events than did COPD patients without bronchiectasis.