Received: 8 July 2022
Accepted: 6 January 2023
First Online: 23 January 2023
: The Linked register-based HUNT-cohort were approved by the Data Inspectorate of Norway and by the Regional Committee for Medical Research Ethics (reference 101,672), and all information from the HUNT was treated according to the guidelines of the Data Inspectorate. Participation was based on informed consent from participants aged 16 years or older. In accordance with Norwegian law, the parents of those younger than 16 years consented on behalf of their child. Linked register-based-cohort: Each individual’s personal identification number were converted to a unique pseudonym at Statistics Norway (trusted third party). The pseudonym was replaced by a project-specific running number. The identification code is stored at Statistics Norway, and only anonymous data was available to the researchers. Data were linked at an individual level based on the project-specific running number. Register-data available to the project were stored and analysed on secured servers at University of Agder in line with recommendations from the Data Protection Officer.
: Not applicable.
: The authors have no conflicts of interest to declare.