Received: 27 February 2019
Accepted: 20 March 2019
First Online: 11 April 2019
Ethics approval and consent to participate
: The study was approved by the Danish National Board of Health, reference number 3–3013-1416/1/and the National Data Protection Agency PVH-2015-004, I-Suite number: 04330. All participants gave informed consent. The National Ethics Committee was consulted, and approval was not deemed necessary H-15016323.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.