1 Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, 510275 Guangzhou, China; Sun Yat-sen Global Health Institute, Institute of State Governance, Sun Yat-sen University, 510275 Guangzhou, China.
2 School of Medicine, Research Centre for Public Health, Tsinghua University, Beijing, China.
3 Sun Yat-sen Global Health Institute, Institute of State Governance, Sun Yat-sen University, 510275 Guangzhou, China.
4 Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, 510275 Guangzhou, China; Sun Yat-sen Global Health Institute, Institute of State Governance, Sun Yat-sen University, 510275 Guangzhou, China. Electronic address: xudong5@mail.sysu.edu.cn.