Prevalence of asthma-COPD overlap in COPD and severe asthma cohorts

Abstract

<b>Background:</b> Asthma and chronic obstructive pulmonary disease (COPD) are airway diseases with similar clinical manifestations, despite differences in pathophysiology. There have been few reports regarding the prevalence of ACO in COPD and severe asthma cohorts. ACO is heterogeneous; patients can be classified on the basis of phenotype differences. <b>Aims:</b> This study was performed to analyze the prevalence of ACO in COPD and severe asthma cohorts. In addition, this study compared baseline characteristics among ACO patients according to phenotype. <b>Methods:</b> Patients with COPD were prospectively enrolled into the Korean COPD subgroup study (KOCOSS) cohort. Patients with severe asthma were prospectively enrolled into the Korean Severe Asthma Registry (KoSAR). ACO was defined in accordance with the updated Spanish criteria. Patients with ACO were divided into four groups according to smoking history (threshold: 20 pack-years) and blood eosinophil count (threshold: 300 cells/μL). <b>Results:</b> The prevalence of ACO significantly differed between the COPD and severe asthma cohorts (19.8% [365/1839] vs. 12.5% [104/832], respectively, P &lt; 0.001).&nbsp;Age, sex, BDR, comorbidities, and medications significantly differed among the four groups. <b>Conclusion:</b> The prevalence of ACO differed between COPD and severe asthma cohorts.&nbsp;ACO patients can be classified into four phenotype groups, such that each phenotype exhibits distinct characteristics.