Published on in Vol 21 , No 6 (2019) :June
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/10924, first published
.

1 Department of Public Health, University of Copenhagen, Copenhagen, DK
2 Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, AU
3 Region Zeeland, Sorø, DK