Text and Data Mining valid from 2018-07-13
Received: 21 April 2018
Accepted: 5 July 2018
First Online: 13 July 2018
Ethics approval and consent to participate
: The study was approved by the Danish Data Protection Agency (North Denmark Region record number 2008–58-0028 and project identification number 2017–70). Informed consent from patients is not required for registry-based studies according to Danish law.
: Not applicable.
: The authors declare that they have no competing interests.
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