Ethics approval and consent to participate
The Regional Committee for Medical and Health Research Ethics in South East Norway found the study to be outside the Norwegian Health Research Act (ref ID: 2017/2172, 20 December 2017). In accordance with Norwegian law, the study was approved by Norwegian Centre for Research Data (ref ID: 556662 and 359479), the Data Protection Official for Vestfold Hospital Trust at the time the study was conducted. This study was performed in line with the principles of the Declaration of Helsinki.