Text and Data Mining valid from 2018-06-23
Received: 1 December 2017
Accepted: 31 May 2018
First Online: 23 June 2018
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of the Medical Faculty of the Technical University of Munich (reference number 335/15). All participants gave oral consent to participate in the completely anonymous study. Participants were not asked to give written informed consent because this would have implied to document their identity resulting in pseudonymized instead of anonymized data collection. The ethics committee approved this approach.
: The authors declare that they have no competing interests.
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