Funding for this research was provided by:
Medicinska fakulteten, Umeå Universitet
Received: 12 August 2019
Accepted: 25 February 2020
First Online: 4 April 2020
Ethics approval and consent to participate
: The Regional Ethical Review Board in Umeå has approved the study (2013–268-31Ö). Only children whose parents have given written informed consent were included in the study. The study was carried out according to the ethical principles available in the Helsinki Declaration of 1975 (as revised in 1983).
: Not applicable.
: The authors declare that they have no competing interests.