©Paula Littlejohn, Irene Cop, Erin Brown, Rimi Afroze, Karen M Davison. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 11.06.2018.
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 JMIR Research Protocols, is properly cited. The complete bibliographic information, a link to the original publication on http://www.researchprotocols.org, as well as this copyright and license information must be included.