[1] China-Japan Friendship Hospital,Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine
[2] Chinese Academy of Medical Sciences,Graduate School of Peking Union Medical College
[3] National Center for Respiratory Medicine,Institute of Respiratory Medicine
[4] Chinese Academy of Medical Sciences,undefined
[5] National Clinical Research Center for Respiratory Diseases,undefined
[6] WHO Collaborating Centre for Tobacco Cessation and Respiratory Diseases Prevention,undefined