Funding for this research was provided by:
Liaison Committee for education, research, and innovation in Central Norway (2016/29014, 17/38297)
Received: 26 November 2019
Accepted: 23 April 2020
First Online: 2 May 2020
Ethics approval and consent to participate
: All participants in HUNT2 gave written and informed consent for the use of their data in research, including linkage. The study was approved by the Regional Committee for Medical and Health Research Ethics in South East Norway (2017/734/REC South East), the data access committee for Health Trust Nord-Trøndelag and the data access committee from the HUNT Study.
: Not applicable.
: The authors declare that they have no competing interests.