Text and Data Mining valid from 2019-11-05
Received: 2 May 2019
Accepted: 23 October 2019
First Online: 5 November 2019
Ethics approval and consent to participate
: This study was approved by the local ethic commission from the Medical Faculty of RWTH Aachen University (EK 187/17). All participants provided informed consent prior to their participation.
: Not applicable.
: The authors declare that they have no competing interests.