Funding for this research was provided by:
Received: 12 October 2018
Accepted: 3 January 2019
First Online: 11 January 2019
Ethics approval and consent to participate
: The Scientific Ethics Committee of Copenhagen County (J.nr.: H-15009660) approved the study and the study was approved by the Danish Data Protection Agency (Journal nr.: 2012-58-0004). All participants gave informed written consent for participation. The study was conducted according to the Helsinki Declaration.
: Not applicable.
: The authors declare that they have no competing interests.
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