Funding for this research was provided by:
Forskningsrådet om Hälsa, Arbetsliv och Välfärd (2012–1736)
Received: 27 February 2018
Accepted: 24 January 2019
First Online: 6 February 2019
Ethics approval and consent to participate
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study no formal approval from an ethical review board was required. Informed consent was obtained from all individual participants included in the HBSC study.
: Not applicable.
: The authors declare that they have no competing interests.
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