Received: 18 March 2019
Accepted: 30 December 2019
First Online: 10 January 2020
Ethics approval and consent to participate
: The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation (approved by the Regional Committee for Medical Research Ethics, South-Eastern Norway; 2014/2046) and with the Helsinki Declaration of 1975, as revised in 2008. Caregivers of participants gave written informed consent before participation.
: Not applicable.
: The authors declare that they have no competing interests.