1. Centre for Health Behaviours Research, School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
2. Centre for Medical Anthropology and Behavioral Health, Sun Yat-sen University, Guangzhou, China
3. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
4. Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, China
5. Department of HIV/AIDS Prevention, Dazhou Center for Disease Control and Prevention, Dazhou, China