Funding for this research was provided by:
Norges Forskningsråd (256681/H10)
Text and Data Mining valid from 2019-05-10
Received: 27 August 2018
Accepted: 3 May 2019
First Online: 10 May 2019
Ethics approval and consent to participate
: The study is approved by the Norwegian Centre for Research Data (2017/52324 and 54855). All participants signed written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.