A Non-interventional Study to Investigate the Current Situation of Asthma-COPD Overlap Syndrome in Patients Over Age 40 With Persistent Airflow Limitation in China

Research Site, Beijing

Research Site, Chongqing

Research Site, Guangzhou

Research Site, Haikou

Research Site, Zhengzhou

Research Site, Changsha

Research Site, Hohhot

Research Site, Shenyang

Research Site, Shanghai

Research Site, Xi’an

Research Site, Chengdou

Research Site, Tianjin

Research Site, Hangzhou