Published on in Vol 6, No 11 (2018): November
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/11508, first published
.
1 XiangYa School of Public Health, Central South University, Changsha, China
2 Hunan Provincial Maternal and Child Health Hospital, Changsha, China
3 Sun Yat-sen Global Health Institute, School of Public Health and Institute of State Governance, Sun Yat-sen University, Guangzhou, China