The impact of COPD-bronchiectasis association on clinical outcomes: insights from East Asian cohorts validating the ROSE criteria.

Background: The radiology, obstruction, symptoms and exposure (ROSE) criteria provide a standardised approach for identifying the "COPD-bronchiectasis (BE) association." However, the clinical implications and outcomes of the COPD-BE association in East Asian populations remain unclear. Our study applied the ROSE criteria to assess the prevalence, clinical impact and outcomes of the COPD-BE association in an East Asian cohort, and compared that cohort with nonsmoking BE patients with fixed airflow obstruction (FAO) and those without FAO.

Methods: An integrated cohort analysis was conducted within a Taiwanese demographic, combining a prospective cohort of 147 participants with a multicentre retrospective cohort of 574 participants. Stratification was based on the ROSE criteria, distinguishing between nonsmoking BE, smoking BE, nonsmoking BE with FAO and BE in compliance with the ROSE criteria. Clinical, radiological and spirometric variables were assessed in conjunction with outcomes to validate the diagnostic utility of the criteria.

Results: Using the ROSE criteria, we found that 16.5% of participants had a COPD-BE association (22.4% in the prospective cohort and 14.9% in the retrospective cohort), predominantly in older male patients. These patients had escalated dyspnoea scores, higher COPD diagnosis rates and increased use of inhalation therapies, compared with those without FAO. Notably, patients with a COPD-BE association and nonsmoking BE with FAO displayed similar clinical symptoms, pulmonary function and disease severity, but differed slightly in airway microbiology. Furthermore, patients with a COPD-BE association had significantly higher risks of exacerbations and hospitalisations, even after adjusting for confounding factors, which highlights that they have poorer clinical outcomes than other groups.

Conclusion: The ROSE criteria effectively identify the COPD-BE association in East Asian populations, highlighting a significant future exacerbation risk compared with other BE groups. Future research is warranted to better understand BE progression, especially in FAO subgroups.