Received: 6 June 2019
Accepted: 26 November 2019
First Online: 10 January 2020
Ethics approval and consent to participate
: The Regional ethical medical committee (REK-Nord) defined the study as a quality control on 15.12.2014 (case number 2014/1883). The data protection officer at the UNN approved the analysis of data from the Level 1 trauma centre on 30.06.15 (case number 0446), without approved consent from the patients in the population, as the study is a quality control.
: Not applicable
: The authors declare that they have no competing interests.