Text and Data Mining valid from 2019-01-18
Received: 9 July 2018
Accepted: 4 January 2019
First Online: 18 January 2019
Ethics approval and consent to participate
: This study was approved by the Regional Committee for Medical Research Ethics in South-Eastern Norway. In addition, the Higher Prosecuting Authority in Norway, the Norwegian Institute of Public Health and Oslo University Hospital Data Inspectorate approved the study. The National Board of Forensic Medicine and the National Board of Health and Welfare in Sweden also approved the study.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.