Received: 4 July 2018
Accepted: 4 March 2019
First Online: 12 March 2019
Ethics approval and consent to participate
: The Danish Data Protection Agency approved the data collection (nr.2001-54-0180). No consent is required from survey participants according to the guidelines of the Danish Data Protection Agency [CitationRef removed].
: Not applicable.
: The authors declare that they have no competing interests.
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