Text and Data Mining valid from 2020-01-06
Received: 30 October 2019
Accepted: 20 December 2019
First Online: 6 January 2020
Ethics approval and consent to participate
: Informed consent was obtained from all individual participants included in the study. The study was conducted according to the Helsinki Declaration (Ethical Principles for Medical Research Involving Human Subjects) and was approved by the University of Tuebingen ethics committee.
: Not applicable.
: The authors declare that they have no competing interests.