[1] Chengdu Ctr Dis Control & Prevent, Chengdu 610041, Sichuan, Peoples R China
[2] West China Matern & Childrens Hosp, West China Hosp 2, Chengdu 610041, Sichuan, Peoples R China
[3] Sichuan Univ, West China Res Ctr Rural Hlth Dev, Chengdu 610041, Sichuan, Peoples R China
[4] Sichuan Univ, West China Sch Publ Hlth, Dept Epidemiol & Hlth Stat, Chengdu 610041, Sichuan, Peoples R China
[5] Sichuan Univ, West China Hosp 4, Chengdu 610041, Sichuan, Peoples R China
[6] Swinburne Technol Univ, Fac Hlth Art & Design, Melbourne, Australia
[7] West China Sch Publ Hlth, Dept Hlth Policy & Management, 16 Sect South Renmin Rd, Chengdu 610041, Sichuan, Peoples R China
[8] West China Fourth Hosp, 16 Sect South Renmin Rd, Chengdu 610041, Sichuan, Peoples R China
[9] China Ctr Dis Control & Prevent, Natl Ctr Women & Childrens Hlth, Beijing 100050, Peoples R China