Published on in Vol 20 , No 5 (2018) :May
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/8347, first published
.

1 Danish Multiple Sclerosis Society, Valby, DK
2 Department of Public Health, University of Copenhagen, Copenhagen, DK
3 Danish Cancer Research Center, Danish Cancer Society, Copenhagen, DK
4 Scias, Copenhagen, DK
5 Steno Diabetes Center Copenhagen, Gentofte, DK