Ytre-Hauge, Kristian S.
Fjæra, Lars Fredrik
Rørvik, Eivind
Dahle, Tordis J.
Dale, Jon Espen
Pilskog, Sara
Stokkevåg, Camilla H.
Article History
Received: 15 November 2019
Accepted: 23 March 2020
First Online: 10 April 2020
Competing interests
: The study has been reviewed and approved by the Regional Committees for Medical and Health Research Ethics (REC) according to Norwegian law and regulations. Informed consent has been obtained from parents or legal guardian of the participants.