Background: In clinical practice, patients whose airway disease shares features of both asthma and chronic obstructive pulmonary disease (COPD) remain poorly recognized.
Material and methods: The study population consisted of 1546 patients with a diagnosis of asthma or COPD or both. Based on patient-reported outcomes and retrospective medical record data, the study population was divided into three groups: ( 1 ) asthma only, ( 2 ) COPD only, and ( 3 ) both asthma and COPD (overlap syndrome group). We evaluated patient characteristics associated with health-related quality of life (HRQoL).
Results: In many respects, the overlap group fell between the asthma and COPD groups. In the overlap group, however, HRQoL was the poorest of all. In the logistic regression model, with the asthma group as the reference, both the overlap and the COPD group showed higher risk for low HRQoL [odd ratio (OR): 1.9; 95% confidence interval (CI): 1.2-3.2; and OR: 1.8, 95% CI: 1.0-3.2; respectively]. In addition, female gender, obesity, duration of disease, disability pension, and coexisting cardiovascular disease were associated with low HRQoL across the study population.
Conclusions: Patients with overlapping asthma and COPD differed from those patients with asthma or COPD only. Overlap syndrome was associated with low HRQoL.