Text and Data Mining valid from 2020-02-04
Received: 6 November 2018
Accepted: 21 October 2019
First Online: 4 February 2020
Ethics approval and consent to participate
: The study was approved by the ethics committee of Charite - Universitätsmedizin Berlin by number EA1/134/12. The study was conducted in compliance with the declaration of Helsinki and written informed consent was obtained.
: Not applicable.
: The authors declare that they have no competing interest.