Published on in Vol 21, No 1 (2019): January
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/9711, first published
.
1 Marshfield Clinic Research Institute, National Farm Medicine Center, Marshfield, WI, United States
2 University of Washington and Puget Sound Veterans Administration, Seattle, WA, United States