Text and Data Mining valid from 2020-02-15
Received: 15 December 2019
Accepted: 3 February 2020
First Online: 15 February 2020
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in this study were in accordance with the ethical standards of the University of Greifswald, Faculty of Medicine (study reference number: BB 188/17) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. All study participants gave their informed consent prior to their inclusion in the study.