Funding for this research was provided by:
County Council of Västerbotten
The Swedish Medical Society
Received: 15 May 2019
Accepted: 31 July 2020
First Online: 12 August 2020
Ethics approval and consent to participate
: The study protocol was approved by the Regional Ethical Review Board in Umeå, diary number 06–144 M, 2010-40-23 and 2011/19–32 M and by the Swedish National Computer Data Inspector Board, and compiles with the Declaration of Helsinki. All participants gav informed consent for future use of data and blood samples at the moment of the baseline survey.
: Data was de-identified, after collection, and therefore there was no consent required from individual patients, according to the ethical approval.
: The authors declare that they have no competing interests.