1. Department of Respiratory Medicine, Yan’an University Affiliated Hospital, Yan’an 716000, China
2. Department of Pulmonology, Weifang Traditional Chinese Hospital, Weifang 261041, China
3. Endoscopy Room, Tai’an Maternal and Child Health Hospital, Tai’an 271000, China
4. Department of Geriatrics, Yan’an University Affiliated Hospital, Yan’an 716000, China
5. Department of Respiratory Medicine, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou 310005, China