Background: Asthma-COPD overlap syndrome (ACOS) has been described and acknowledged as a distinct clinical entity; however, its characteristics in daily clinical practice are largely unknown. The aim of this study was to identify the prevalence of ACOS in the real-life population, its pattern of comorbidities, and its impact on hospitalization risk.
Methods: Data for this retrospective cohort study were extracted from the Majorca Real-Life Investigation in COPD and Asthma cohort, including primary care, hospitalization, and pharmacy data from the Balearic Islands, Spain. Patients who had received a physician-confirmed diagnosis of both asthma and COPD were identified as having ACOS and compared with a COPD-only population. In subanalyses, more stringent diagnostic criteria (Global Initiative for Asthma-Global Initiative for Chronic Obstructive Lung Disease) were applied. The pattern and impact of comorbidities on all-cause hospitalization were compared by multivariate logistic regression.
Results: In total, 5,093 patients with ACOS (prevalence, 5.55 per 1,000 inhabitants) were compared with 22,778 patients with COPD (30.40 per 1,000 inhabitants). Patients with ACOS were more frequently female (53.4%) than were patients with COPD (30.8%), younger (ACOS, 64.0 years; COPD, 65.8 years), and differed by nonsmoking status (ACOS, 41.4%; COPD, 22.1%) (all, P < .001). In adjusted analyses, allergic rhinitis (OR, 1.81; 95% CI, 1.63-2.00), anxiety (OR, 1.18; 95% CI, 1.10-1.27), gastroesophageal reflux disease (OR, 1.18; 95% CI, 1.04-1.33), and osteoporosis (OR, 1.14; 95% CI, 1.04-1.26) were more frequent in ACOS than COPD. In contrast, chronic kidney disease (OR, 0.79; 95% CI, 0.66-0.95) and ischemic heart disease (OR, 0.88; 95% CI, 0.79-0.98) were less frequent. In patients with ACOS, cardiovascular diseases showed the strongest association with hospitalization.
Conclusions: ACOS is prevalent in the general population, and it affects to a large extent females with less smoking exposure compared with patients with COPD only. Cardiovascular comorbidities in particular contribute most to overall hospitalization risk of patients with ACOS.
Keywords: COPD; asthma; asthma-COPD overlap; epidemiology (pulmonary).
Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.