1. Guangzhou Baiyun District Center for Disease Control and Prevention, Guangzhou, People’s Republic of China
2. Department of Epidemiology and Health Statistics, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
3. School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
4. Department of Preventive Medicine, School of Basic Medicine and Public Health, Jinan University, Guangzhou, People’s Republic of China