Published on in Vol 8, No 11 (2019): November
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/14180, first published
.
1 University of Pennsylvania, Philadelphia, PA, United States
2 Penn Medicine Nudge Unit, Philadelphia, PA, United States
3 Crescenz Veteran Affairs Medical Center, Philadelphia, PA, United States