Funding for this research was provided by:
Nasjonalforeningen for Folkehelsen (12906)
Helse Sør-Øst RHF (2013111)
Received: 5 September 2019
Accepted: 11 August 2020
First Online: 17 August 2020
Ethics approval and consent to participate
: All participants provided written informed consent prior to inclusion. The study was approved by the regional ethic committees in Norway, Sweden and Denmark. The study is conducted according to the Helsinki Declaration. ExternalRef removed identifier NCT01796379.
: Not applicable.
: The authors declare that they have no competing interests.