Prevalence and characteristics of asthma–COPD overlap syndrome identified by a stepwise approach

Abstract

Background and objectiveThere is increasing recognition of asthma–COPD overlap syndrome (ACOS), which shares some features of both asthma and COPD; however, the prevalence and characteristics of ACOS are not well understood. The aim of this study was to investigate the prevalence of ACOS among patients with COPD and its characteristics using a stepwise approach as stated in the recent report of the Global Initiative for Asthma (GINA) and the Global Initiative for Chronic Obstructive Lung Disease (GOLD).MethodsThis multicenter, cross-sectional, observational study enrolled outpatients who were receiving medical treatment for COPD. Clinical data, including spirometry results, were retrieved from medical records. For symptom assessment, patients were asked to complete the Clinical COPD questionnaire and the modified British Medical Research Council questionnaire.ResultsOf the 1,008 patients analyzed, 167 (16.6%) had syndromic features of ACOS. Of the total number of patients, 93 and 42 (9.2% and 4.2%) also had a predefined clinical variability of ≥12%/≥200 mL and ≥12%/≥400 mL in forced expiratory volume in 1 second (FEV1), respectively, and therefore were identified as having ACOS. Conversely, the number of patients who had either syndromic or spirometric feature of ACOS was 595 (59.0%, ≥12%/≥200 mL FEV1 clinical variability), and 328 patients (32.5%, ≥12%/≥400 mL FEV1 clinical variability) had both the features. Patients identified as having ACOS were of significantly younger age, had a shorter duration of COPD, lower number of pack-years, better lung function, milder dyspnea symptoms, and higher peripheral blood eosinophil values compared with patients with COPD alone. The rate of exacerbations in the previous year was not significantly different between the ACOS and COPD groups.ConclusionUsing a stepwise approach, as stated in the GINA/GOLD report, the proportions of patients identified as having ACOS were found to be 9.2% and 4.2% (depending on the FEV1 variability cutoff used) among the 1,008 outpatients medically treated for COPD in a real-life clinical setting.

Clinical Characteristics and Changes of Clinical Features in Patients with Asthma-COPD Overlap in Korea according to Different Diagnostic Criteria

“…The age differences between the ACO and non-ACO groups defined according to each category was not evident. This is contrary to the previous studies by Kobayashi et al, and Inoue et al, in which the ACO groups showed significantly younger mean age when compared to the non-ACO groups 15,16 . In addition, the ACO groups had significantly higher proportions of patients with a past history of asthma and atopy, as reported in previous studies on ACO 15,17 .…”

Concomitant diagnosis of asthma and COPD: a quantitative study in UK primary care

“… 12 A recent multicentre study on patients with COPD in Japan found an asthma prevalence of 9.2% or 4.2%, depending on the FEV1 cut-off. 24 Other studies report a very wide range of prevalence of concomitant asthma and COPD as the diagnosis criteria are heterogeneous and a consensus on diagnostic criteria is needed. 4 , 5 …”

Health characteristics of patients with asthma, COPD and asthma–COPD overlap in the NHANES database

“…1 , 2 Participants with characteristics of both diseases are classified as having asthma–COPD overlap (ACO). 3 – 5 The 2018 Global Initiative for Asthma (GINA) describes ACO as being characterized by persistent airflow limitation with several features of asthma (ie, current or historical variability of airway limitation, personal and/or family history of asthma, allergies, and symptoms that are partially but significantly reduced by treatment) and COPD (ie, age of onset ≥40 years, associated with progression, chest X-ray with severe hyperinflation, additional COPD-like changes, and comorbidities that contribute to impairment). 1 , 6 Generally, participants with ACO experience more frequent exacerbations, poorer quality of life, more progressive lung function deterioration, and elevated health care utilization in comparison to asthma or COPD alone.…”