Vorobieva S. Jensen, V.
Furberg, A-S
Slotved, H-C
Bazhukova, T.
Haldorsen, B.
Caugant, D. A.
Sundsfjord, A.
Valentiner-Branth, P.
Simonsen, G. S.
Article History
Received: 12 November 2019
Accepted: 27 March 2020
First Online: 15 April 2020
Ethics approval and consent to participate
: Ethical approval was obtained from the Ethics Research Committee of the Northern State Medical University, Russia on the 6th of June, 2006, the reference number for the approval 06/06, and from the Ethics Research Committee of North Norway on the 23rd of June 2006, the reference number of the approval 5.2006.2086. The permission to carry out the study was sought from the authorities of the Arkhangelsk region. All parents/guardians were informed about the study by informational letters and a majority of the parents/guardians participated in informational meetings. The written informed consents were signed by parents or guardians for all participants of the study. There was a questionnaire that parents or guardians filled out for all participants of the study.
: Consent for publication does not apply.
: Hans-Christian Slotved is involved with projects supported by Pfizer. All other authors had declare that they have no competing interests.