Text and Data Mining valid from 2019-11-15
First Online: 15 November 2019
Compliance with Ethical Standards
: All procedures performed in studies involving human participants were in accordance with the ethical standards of national research committee in Denmark and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.
: The author declares that there are no conflicts of interest.