Jenssen, Astrid Bjørke
Stovner, Lars Jacob
Tronvik, Erling
Sand, Trond
Helde, Grethe
Gravdahl, Gøril Bruvik
Hagen, Knut http://orcid.org/0000-0003-2111-8895
Article History
Received: 11 November 2019
Accepted: 15 December 2019
First Online: 27 December 2019
Ethics approval and consent to participate
: The present study (2017/2050/REK Midt) and all the four original studies were approved by the Regional Committee for Ethics in Medical Research. The two last studies were also approved by the Norwegian Medicines Agency (not needed for the two first studies). The participants have given written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.