1. College of Public Health; Zhengzhou University; Zhengzhou 450001 Henan People's Republic of China
2. Department of Geriatrics; The Second Affiliated Hospital of Zhengzhou University; Zhengzhou 450014 Henan People's Republic of China
3. Department of Pulmonary and Critical Care Medicine; The First Affiliated Hospital of Zhengzhou University; Zhengzhou 450052 Henan People's Republic of China
4. School of Public Health; Xinxiang Medical University; Xinxiang 453003 Henan People's Republic of China