Blinkenberg, Jesper
Hetlevik, Øystein
Sandvik, Hogne
Baste, Valborg
Hunskaar, Steinar
Article History
Received: 10 August 2021
Accepted: 21 December 2021
First Online: 15 January 2022
Declarations
:
: The Regional Ethical Committee for Medical and Health Research Ethics, Region West approved the project (30.01.2014) (reference number 2013/2344/REK vest). The Regional Ethical Committee for Medical and Health Research Ethics, Region West also waived the requirement of the informed consent for the study. Norwegian Data Protection Authority approved the use of the data for research purposes in this project (15.09.2014) (reference number 14/0322–9/CGN). The register owners, Statistics Norway and the Norwegian Directorate of Health, approved linkage of registries. The data were pseudo anonymized by third party (Statistics Norway) and analysed at group level to minimize the risk for backwards identification of individuals. All analyses were carried out, and methods were used, in accordance with relevant guidelines and regulations (declaration of Helsinki).
: Not applicable.
: The authors declare that they have no competing interests.