Received: 11 May 2018
Accepted: 15 November 2018
First Online: 27 November 2018
Ethics approval and consent to participate
: In compliance with Norwegian legislation on ethics in research, the study was regarded as health service research and was approved by the Norwegian Data Ethical Approval: Data Protection Official for Research, Norwegian Social Science Data Service (Project no 50435). Each participant provided written consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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