Funding for this research was provided by:
UiT The Arctic University of Norway (Publication fund of UiT The Arctic University of Norway: Code: IN-1096130)
Received: 9 September 2021
Accepted: 29 October 2021
First Online: 25 November 2021
: The study is based on secondary use of clinical administrative data. For this reason, approval from Regional Committees for Medical and Health Research Ethics (REK) is not required, but REK has given exemption from the duty of confidentiality (ref. 20627/REK sør-øst A). The project has conducted a Data Protection Impact Assessment (DPIA). Public access to this type of data is closed. Access was given by applying to the NPR, the CRN and the SSB. According to Norwegian law, further ethical approval or obtaining informed consent was not required for this study. All methods were performed in accordance with the relevant guidelines and regulations.
: Not required.
: None declared.