Eide, I A
Dahle, D O
Svensson, M
Hartmann, A
Åsberg, A
Bjerve, K S
Christensen, J H
Schmidt, E B
Lauritsen, M E
Lund, K
Jenssen, T
Article History
Received: 10 November 2015
Revised: 6 January 2016
Accepted: 13 January 2016
First Online: 2 March 2016
Competing interests
: The authors declare no conflict of interest.