Published on in Vol 8, No 8 (2020): August
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/20071, first published
.
1 Department of Obstetrics and Gynaecology, Kwong Wah Hospital, Hong Kong SAR, China (Hong Kong)
2 Institute of Health Research, University of Notre Dame, Fremantle, Western Australia, Australia
3 Department of Public Health and Preventive Medicine, School of Medicine, Jinan University, Guangzhou, China