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Article History

Received: 2 June 2017

Accepted: 20 March 2018

First Online: 2 April 2018

Ethics approval and consent to participate

: Approval for this study was given by the ethics committee of the Medical Faculty of Erlangen-Nuremberg University (registration number 227_14B). By voluntarily returning the questionnaire, the participants consented to the anonymous use of their data.

: Not applicable.

: The authors declare that they have no competing interests.

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