Received: 2 April 2018
Accepted: 26 July 2018
First Online: 13 August 2018
Ethics approval and consent to participate
: According to the Professional Code of the German Medical Association (article B.III. § 15.1) neither informed consent nor approval of an ethics committee was needed. Nonetheless patients provided informed consent that their data may be used for scientific purposes at the time of hospital admission which is the general policy of our institution. The ethical committee of hannover Medical School further stated that no approvement is needed. Patient records and patient data were anonymized and de-identified prior to analysis.
: Not applicable.
: The authors declare that they have no competing interests.
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