1. Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China
2. Hospital Service Management Office, Peking University Third Hospital, Beijing, China
3. Department of Global Health, School of Public Health, Peking University Health Science Center, Beijing, China
4. Institute for Immunization and Prevention, Beijing Center for Disease Prevention and Control, Beijing, China
5. Department of Biomedical Informatics, School of Basic Medicine, Peking University Health Science Center, Beijing, China