1. Department of Respiratory and Critical Care Medicine, West China Hospital/West China School of Medicine, Sichuan University, Chengdu, China
2. Department of Integrated Traditional and Western Medicine, West China Hospital, Sichuan University, Chengdu, China
3. Department of Periodical Press and National Clinical Research Center for Geriatrics and Chinese Evidence-based Medicine Center and Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, China