Published on in Vol 6, No 2 (2018): April-June
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/9571, first published
.
1 School of Public Health, Department of Epidemiology and Biostatistics, Indiana University Bloomington, Bloomington, IN, United States
2 School of Public Health, Department of Kinesiology, Indiana University Bloomington, Bloomington, IN, United States