1. Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of China
2. Department of Thoracic Surgery, First Affiliated Hospital of Guangzhou Medical University & Guangzhou Research Institute of Respiratory Disease, Guangzhou, People's Republic of China
3. Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA