1. School of Public Health, Peking University , Beijing , China
2. China Center for Health Development Studies, Peking University , Beijing , China
3. Department of Integrated Traditional Chinese and Western Medicine, Peking University First Hospital , Beijing , China
4. Division of Injury Prevention and Mental Health, National Center for Chronic and Noncommunicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing , China
5. Institute of Reproductive and Child Health, Ministry of Health Key Laboratory of Reproductive Health and Department of Epidemiology and Biostatistics, School of Public Health, Peking University , Beijing , China
6. Global Health Institute and the Nicholas School of Environment, Duke University , Durham, North Carolina , USA
7. Ultrasonic Department, The Third Medical Center of Chinese People’s Liberation Army General Hospital , Beijing , China
8. Key Laboratory of Epidemiology of Major Diseases (Peking University), Ministry of Education , Beijing , China