Published on in Vol 7, No 4 (2019): April
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/11720, first published
.
1 Stanford Prevention Research Center, Stanford University School of Medicine, Stanford, CA, United States
2 Department of Health Sciences, California State University, East Bay, Hayward, CA, United States
3 Quantitative Sciences Unit, Stanford University School of Medicine, Stanford, CA, United States