Received: 4 July 2018
Accepted: 11 July 2019
First Online: 22 July 2019
Ethics approval and consent to participate
: The study was considered a quality assurance project, which, according to Norwegian law on medical research, does not require an approval by the Regional Ethics Committee, nor a written patient consent. The local Data Protection Authorities approved the study (reference number 15–148).
: Not Applicable.
: The authors declare that they have no competing interests.