1. Department of Epidemiology and Biostatistics, School of Public Health, Peking University, No.38, Xueyuan Road, Haidian District, Beijing 100191, China
2. Center for Primary Care and Outcomes Research, School of Medicine, Center for Health Policy, Freeman Spogli Institute for International Studies, Stanford University, 450 Jane Stanford Way, Stanford, CA 94305-2004, USA
3. Institute for Global Health and Development, Peking University, No.5, Yiheyuan Road, Haidian District, Beijing 100871, China
4. Global Center for Infectious Disease and Policy Research & Global Health and Infectious Diseases Group, Peking University, No.38, Xueyuan Road, Haidian District, Beijing 100191, China
5. Key Laboratory of Reproductive Health, National Health and Family Planning Commission of the People’s Republic of China, No.38, Xueyuan Road, Haidian District, Beijing 100191, China