1Department of Poisoning and Occupational Diseases, Shandong University, Emergency Medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China

2School of Public Health, Cheeloo College of Medicine, Shandong University, Shandong University, Jinan, Shandong, China

3School of Nursing, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China

4Department of Geriatric Medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China

Xiangdong Jian, Department of Poisoning and Occupational Diseases, Emergency Medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107 Wenhuaxi Road, Jinan, Shandong 250012, China. Email: [email protected] Baotian Kan, Department of Geriatric medicine, Qilu Hospital, Cheeloo College of Medicine, Shandong University, No. 107, Road Wenhuaxi, Jinan, 250012 Shandong, China. E-mail:[email protected]