Published on in Vol 6, No 3 (2018): Jul-Sep
                                    Preprints (earlier versions) of this paper are
                                    available at
                                    https://preprints.jmir.org/preprint/10295, first published
                                    .
                                

1 Chair of Medical Informatics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
2 NewTec GmbH, Pfaffenhofen a.d. Roth, Germany
3 Chair of Health Psychology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
