1. Tobacco Medicine and Tobacco Cessation Center; China-Japan Friendship Hospital; Beijing China
2. Department of Respiratory Medicine, Zhongshan Hospital; Fudan University; Shanghai China
3. Clinical Trials Service Unit; Oxford University; Oxford United Kingdom
4. China-Japan Friendship Hospital; Beijing China
5. Department of Respiratory Medicine; Capital Medical University; Beijing China
6. National Clinical Research Center for Respiratory Diseases; Beijing China