Text and Data Mining valid from 2019-11-09
Received: 15 July 2019
Accepted: 23 October 2019
First Online: 9 November 2019
Ethics approval and consent to participate
: Study was approved by the local ethical committee.Due to the retrospective study design and the anonymization of data, consent to participate was not necessary. An identification of the participants by third is not possible.
: Not applicable.
: The authors declare that they have no competing interests.