Friesgaard, Kristian D.
Riddervold, Ingunn S.
Kirkegaard, Hans
Christensen, Erika F.
Nikolajsen, Lone
Article History
Received: 20 December 2017
Accepted: 15 June 2018
First Online: 3 July 2018
Ethics approval and consent to participate
: Approved by the Danish Data Protection Agency (no. 1-16-02-294-16) and the National Board of Health (no. 3-3013-1663/1). Observational studies do not require informed patient consent and/or approval from local ethics committees according to Danish Law.
: Not required for observational studies according to Danish law.
: The authors declare that they have no competing interests.
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