1. Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, Guangdong 510080, China
2. School of Public Health, Sun Yat-sen University, No. 74 Zhongshan 2nd Road, Guangzhou, Guangdong 510080, China
3. Guangzhou Municipal Center for Disease Control and Prevention, Guangzhou 0086-510080, China