Received: 17 October 2018
Accepted: 14 March 2019
First Online: 29 March 2019
Ethics approval and consent to participate
: Permission to conduct the study has been granted from the Danish Data Protection Agency (2007-58-0010) and the Danish Health and Medical Authorities (3–3013-552/1/). No further approval was required for this study in Denmark.
: Not applicable
: The authors declare that they have no competing interests.
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