Text and Data Mining valid from 2019-11-01
Received: 22 March 2019
Accepted: 14 October 2019
First Online: 1 November 2019
Ethics approval and consent to participate
: All participants provided written informed consent. Furthermore, all study procedures were in accordance with the 1964 Helsinki declaration and its later amendments and where approved by the Ethics Committee of the RWTH Aachen University (reference number EK 106/14).
: All participants provided written consent to publish all anonymized data reported in this publication. All authors approved the publication of the manuscript in its current form.
: All authors declare that they have no competing interests.