Bickenbach, Johannes
Schöneis, Daniel
Marx, Gernot
Marx, Nikolaus
Lemmen, Sebastian
Dreher, Michael
Article History
Received: 21 December 2017
Accepted: 9 August 2018
First Online: 20 August 2018
Ethics approval and consent to participate
: This observational study received approval from the Institutional Review Board for Human Studies at the Medical Faculty of the University Hospital Aachen, Germany, and need for informed consent was waived. All analyses were conducted according to the principles of the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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