Søgaard, A.J.
Ranhoff, A.H.
Meyer, H.E.
Omsland, T.K.
Nystad, W.
Tell, G.S.
Holvik, K.
Article History
Received: 16 February 2018
Accepted: 28 June 2018
First Online: 13 July 2018
Compliance with ethical standards
: Cohort of Norway and linkages between the data sources were approved by the Regional Committee for Medical and Health Research Ethics (region South-East) and the Norwegian Data Protection Authority. All participants in the CONOR study gave their written informed consent. The CONOR steering committee approved the project. The study has been conducted in full accordance with the Declaration of Helsinki of the World Medical Association
: None.