Received: 26 February 2020
Accepted: 20 July 2020
First Online: 29 July 2020
Ethics approval and consent to participate
: The study was approved by the Regional Ethics Committee, Norwegian University of Science and Technology (NTNU), Trondheim, Norway (REC Central 2015/843). All participants were volunteers and signed an informed consent form.
: Not applicable.
: The authors have no financial or non-financial competing interests.