Published on in Vol 9, No 6 (2020): June
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/15930, first published
.
1 Department of Epidemiology, Faculty of Public Health, Ho Chi Minh City, Vietnam
2 The Sydney School of Public Health, Faculty of Medicine and Health, The University of Sydney, Sydney, Australia