Received: 7 March 2019
Accepted: 14 May 2019
First Online: 22 May 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of the North Denmark Region (N-20170051) and the Danish Data Protection Agency (Doc.nr. 447288) prior to data collection. As this was a registry-based study in which only anonymised data were extracted, there was no need for obtaining informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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