Text and Data Mining valid from 2018-04-05
Received: 25 November 2017
Accepted: 27 March 2018
First Online: 5 April 2018
Ethics approval and consent to participate
: The study was approved by the Danish Data Protection Agency (record number 1–16–02-207-15). See attached file “Ethics Approval”.
: Approval by the local ethics committee and collection of informed consent are not required for observational studies.
: The authors declare that they have no competing interests.
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