Funding for this research was provided by:
Region Örebro län
Received: 10 January 2020
Accepted: 9 July 2020
First Online: 29 July 2020
Ethics approval and consent to participate
: Informed consent to registration in BUSA, given by all registered patients or guardians, includes the use of data in BUSA for research purposes. The Regional Ethical Review Board in Uppsala, Sweden, approved the study (approval no. 2017/118).
: Not applicable.
: The authors declare that they have no competing interests.