Ethical considerations

We have obtained approvals from the National Data Inspection Board, the Norwegian Directorate of Health, Statistics Norway and the Regional Committee for Medical Research Ethics (REK). The data will be handled in accordance with the permissions given by the above listed governmental bodies. The data will be summarized and published in a way that none of the participants may be recognized. The project has obtained approval according to the General Data Protection Regulation regulations (GPDR).

Conflict of interest: None declared