Published on in Vol 6, No 1 (2018): Jan-Mar
                                    Preprints (earlier versions) of this paper are
                                    available at
                                    https://preprints.jmir.org/preprint/8286, first published
                                    .
                                

1 Department of Computer Science, University of Manitoba, Winnipeg, MB, Canada
2 Department of Biomedical Informatics, University of California San Diego, La Jolla, CA, United States
