Funding for this research was provided by:
Universitetet i Bergen
Article History
Received: 7 June 2020
Accepted: 15 October 2020
First Online: 2 November 2020
Ethics approval and consent to participate
: Approval for the study were obtained from the Regional Committee for Medical and Health Research Ethics, western Norway (REC West), 17.3.2011 and 27.10.2016 (2011/481). Norwegian center for research data granted for exemption from the duty of confidentiality (23.12.2016). Data Protection Authoroty gave license for the project (2.2.2017, 16/02094).The participants in HUNT3 signed a declaration of consent when they participated. The consent included use of the material in future approved by an ethical committee.
: Not applicable.
: The authors declare that they have no competing interests.