Text and Data Mining valid from 2019-05-07
Received: 21 December 2017
Accepted: 15 April 2019
First Online: 7 May 2019
Ethics approval and consent to participate
: The KiGGS study was approved by the Charité - Universitätsmedizin Berlin ethics committee and the Federal Office for the Protection of Data in Germany; all legal representatives of the study participants gave written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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