Text and Data Mining valid from 2019-05-23
Received: 9 November 2018
Revised: 30 April 2019
Accepted: 9 May 2019
First Online: 23 May 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The study was conducted in concordance with the Helsinki II declaration. The study was approved by the Danish Regional Ethics Committee, (journal number 2007-58-0010). We certify that all applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research. Mentors were adequately instructed to fulfill their role, and were closely followed and were offered help and supervision if requested.