Published on in Vol 7, No 2 (2019): Apr-Jun
                                    Preprints (earlier versions) of this paper are
                                    available at
                                    https://preprints.jmir.org/preprint/10020, first published
                                    .
                                

1 Partners HealthCare Pivot Labs, Partners HealthCare, Boston, MA, United States
2 Harvard Medical School, Harvard University, Boston, MA, United States
3 Massachusetts General Hospital, Boston, MA, United States
