Funding for this research was provided by:
Universitätsklinikum Hamburg-Eppendorf (UKE)
Received: 12 May 2021
Accepted: 8 October 2021
First Online: 22 October 2021
: The BELLA study was approved by the ethics committee of the University Hospital Charité in Berlin and the Federal Commissioner for Data Protection in Germany. All procedures performed in the BELLA study were in accordance with the 1964 Helsinki declaration and its later amendments. Children, adolescents and their parents needed to give written informed consent prior to participation in the BELLA study. Informed consent was gathered from all participating parents for themselves, from parents for each participating child, and from all participating children and adolescents aged at least 11 years.
: Not applicable.
: The authors declare that they have no competing interests.