Methods Subjects Adult patients suspected of having asthma were recruited from the outpatient Asthma Clinic of West China

Pneumology Group, Department of Integrated Traditional Chinese and Western Medicine, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Psychiatric Laboratory, Department of Psychiatry, West China Hospital, Sichuan University, Chengdu, People’s Republic of China