Funding for this research was provided by:
the Norwegian Research Institute (237784)
Received: 27 June 2017
Accepted: 17 April 2018
First Online: 2 May 2018
Ethics approval and consent to participate
: The study conformed to the principles embodied in the Declaration of Helsinki.Permission to access the data was sought from the participating hospital, which was also responsible for anonymizing the data before being passed on to the project group.The project was reported to the Norwegian Social Science Data Service (NSD), ensuring compliance with all ethical requirements for data collection, data storage, and data handling (ref: 40900 / 3 / LT). NSD is the Data Protection Official for Research for all Norwegian universities and university colleges, as well as for several hospitals and research institutes. According to national regulations, most research must only be submitted to NSD, which also evaluates the need for further ethical approval by the Data Inspectorate (ExternalRef removed). Further ethical approval was not required for this project.
: The author declares that they have no competing interests.
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