Published on in Vol 6, No 4 (2021): Oct-Dec
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/32298, first published
.

1 Foodsmart, San Francisco, CA, United States
2 Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, United States
3 Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States