Funding for this research was provided by:
This study was partly supported by the Research Council of Southeast Sweden (FORSS).
Received: 2 August 2017
Accepted: 6 June 2019
First Online: 1 July 2019
Ethics approval and consent to participate
: All procedures for this study were approved by the Regional Ethical Research Committee at Linköping University (Dnr M41–09). Written informed consent was obtained from all participants.
: No individual’s personal data is included.
: The authors declare that they have no competing interests.