Funding for this research was provided by:
Medizinischen Fakultät Heidelberg, Universität Heidelberg
Received: 25 January 2019
Accepted: 25 March 2019
First Online: 22 May 2019
Ethics approval and consent to participate
: The study was approved by the local institutional review boards/independent ethics committees of each participating center. Informed consent was obtained before any study related procedure.
: Not applicable.
: The authors declare that they have no competing interests.
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