Published on in Vol 5 , No 1 (2018) :Jan-Mar
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/8948, first published
.

1 Faculty of Industrial Design Engineering, Delft University of Technology, Delft, Netherlands
2 Department of Public and Occupational Health and Amsterdam Public Health Research Institute, VU University Medical Center, Amsterdam, Netherlands