Hausmann, F.
Iversen, V. V.
Kristoffersen, M.
Gundersen, H.
Johannsson, E.
Vika, M.
Article History
Received: 23 November 2017
Accepted: 28 March 2018
First Online: 14 April 2018
Compliance with ethical standards
: The study was in accordance with and approved by the Regional Committee for Medical Research Ethics.
: The authors declare that they have no conflict of interest.
: Informed consent was obtained from all individual participants included in the study.