Proportion and exacerbation of asthma-COPD overlap syndrome in China: an interim non-interventional study

Background: GINA 2014 introduced Asthma-COPD overlap syndrome (ACOS), GINA and GOLD 2015 further described it. As ACOS is still poorly recognized in China, further research is needed to improve our understanding and optimize management. Aims and Objectives: To investigate the distributions and characteristics of patients with ACOS, asthma and COPD over age 40 with airflow limitation in China. Methods: This multi-center (20 sites), cross-sectional, non-interventional study (NCT02600221) was planned to collect data from 2,000 patients over age 40 with airflow limitation (post-BD FEV1/FVC<0.7) in China. Interim analysis was performed when enrollment achieved 1,031 patients. Primary endpoint is the proportion of ACOS, and the secondary endpoints include clinical characteristics of ACOS, asthma and COPD. The diagnosis was based on GINA and GOLD 2015 definition. Results: The proportion of ACOS was consistent with other studies (39.4% vs. 15%-55%), but the initial diagnostic rate was much lower (5.7% vs. 15%-20%) (GINA & GOLD 2015). Among 406 ACOS patients, 64.0%, 34.7%, 20.7% and 19.5% was initially diagnosed as asthma, COPD, chronic bronchitis and emphysema. ACOS also stood out with an exacerbation rate of 41.9% (170/406) with average 2.2±2.0 times/person-year (n=170). The exacerbation rate in asthma and COPD was 40.3% (54/134) with average 2.1±1.9 times/person-year and 40.9% (201/491) with 2.0±1.6 times/person-year, respectively, among patients with exacerbation history. Conclusions: Nearly two-fifths patients over age of 40 with airflow limitation in China are ACOS patients with higher exacerbation rate, who are in great need of accurate diagnosis and standard management.