1. Department of Geriatrics, Respiratory Medicine Xiangya Hospital, Central South University Changsha PR China
2. National Clinical Research Center for Geriatric Disorders Xiangya Hospital, Central South University Changsha PR China
3. Clinical Experimental Center, Jiangmen Key Laboratory of Clinical Biobanks and Translational Research Jiangmen Central Hospital, Affiliated Jiangmen Hospital of Sun Yat‐sen University Jiangmen PR China
4. Department of Pathology, Jiangmen Central Hospital Affiliated Jiangmen Hospital of Sun Yat‐sen University Jiangmen PR China
5. Center for Healthcare‐associated Infection Control Xiangya Hospital, Central South University Changsha PR China
6. Department of Respiratory Medicine Xiangya Hospital, Central South University Changsha PR China