Received: 6 April 2021
Accepted: 14 June 2021
First Online: 6 July 2021
: The study protocol was approved 10.11.2015/295§ by the Research Ethics Committee of the Kuopio University Hospital District of Northern Savo, Finland. All the participants and their parents gave their informed written consent for participation. A renewed written consent was given for participation in the 8-year follow up study. The study protocol followed guidelines of declaration of Helsinki.
: All authors have given consent for publication.
: None of the authors declare any conflicts of interest.