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.
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.
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.
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.