Aaseth, E
Fagerland, M W
Aas, A-M
Hewitt, S
Risstad, H
Kristinsson, J
Bøhmer, T
Mala, T
Aasheim, E T
Article History
Received: 13 October 2014
Revised: 22 April 2015
Accepted: 23 April 2015
First Online: 17 June 2015
Competing interests
: The authors declare no conflict of interest.