Funding for this research was provided by:
Helse Sør-Øst RHF (2014073)
Text and Data Mining valid from 2019-12-01
Received: 12 April 2019
Accepted: 29 October 2019
First Online: 2 December 2019
Ethics approval and consent to participate
: The study was conducted in accordance with the Declaration of Helsinki and approved by the Regional Committee for Medical and Health Research Ethics South East Norway; 2013/1264 and 2012/966. Written informed consent was obtained from all participants.
: Not applicable
: The authors declare that they have no competing interests.