Text and Data Mining valid from 2019-12-01
Received: 10 July 2019
Accepted: 28 November 2019
First Online: 5 December 2019
Ethics approval and consent to participate
: The ethics committee of the medical faculty of Charité University Hospital Berlin approved the study (EA4/131/14). All study participants signed an informed consent form.
: Not applicable.
: The authors declare that they have no competing interests.