Funding for this research was provided by:
Deutsche Forschungsgemeinschaft (SCHO 1545/3-1)
China Scholarship Council (201506010268)
Received: 12 September 2018
Accepted: 20 December 2018
First Online: 24 January 2019
Ethics approval and consent to participate
: The ESTHER Study has been approved by the ethics committees of the Medical Faculty of the University of Heidelberg and the Medical Association of Saarland and is being conducted in accordance with the declaration of Helsinki. Written informed consent was obtained from all study participants.
: Not applicable.
: The authors declare that they have no competing interests.
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