Text and Data Mining valid from 2018-09-19
Received: 22 January 2018
Accepted: 12 September 2018
First Online: 19 September 2018
Ethics approval and consent to participate
: The study has been approved by the Norwegian Center for Research Data (NSD) (Reference number: 49331, Date: 01.08.2016). All participants signed written informed consent to participate in the study.
: Not applicable.
: Author SW is a member of the editorial board (Associate Editor) of BMC health services research.
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