Janssen, Martin W. W.
Linxweiler, Johannes
Philipps, Ines
Bütow, Zentia
Siemer, Stefan
Stöckle, Michael
Ohlmann, Carsten-Henning
Article History
Received: 20 October 2017
Accepted: 7 February 2018
First Online: 20 February 2018
Ethics approval and consent to participate
: Ethical approval was obtained from the Aerztekammer des Saarlandes Ethik-Kommission (Ref. number 188/05).
: Not applicable, anonymized databases.
: The authors declare that they have no competing interests.
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