Funding for this research was provided by:
Universitetet i Oslo
Received: 29 June 2019
Accepted: 22 August 2019
First Online: 28 August 2019
Ethical approval and consent to participate
: The Regional Committee for Medical Research Ethics approved the study protocol (The Regional Committee for Medical Research and Ethics reference number 2014/1754) and all the participants gave their written informed consent to participate at baseline and 5-year follow-up.
: Not applicable.
: The authors declare that they have no competing interests.