Funding for this research was provided by:
Norges Forskningsråd (213477)
Text and Data Mining valid from 2018-11-26
Accepted: 22 November 2018
First Online: 26 November 2018
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study was approved by the Regional Committee on Medical and Health Research Ethics, South-East (ID: 2012/1176).
: Informed consent was obtained from all individual participants included in the study.