Received: 9 February 2019
Accepted: 17 July 2019
First Online: 24 July 2019
Ethics approval and consent to participate
: The study protocol was registered and approved by the regional ethical review board in Stockholm, Sweden on January 13th 2016 (Study id: 2015/2078–31/1), and written informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.