Article History
Received: 18 May 2017
Accepted: 17 January 2018
First Online: 25 January 2018
Ethics approval and consent to participate
: The Norwegian Data Inspectorate and the Regional Committee for Ethics in Medical Research approved the HUNT study. The Regional Ethical Committee also approved the present study (REC South East–C, number 2013/1812). Principles governing biomedical research in humans as stated in the Declaration of Helsinki were followed. Each participant gave written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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