©Samineh Sanatkar, Peter Andrew Baldwin, Kit Huckvale, Janine Clarke, Helen Christensen, Samuel Harvey, Judy Proudfoot. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 26.11.2019. This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on http://www.jmir.org/, as well as this copyright and license information must be included.