Text and Data Mining valid from 2019-04-15
Received: 21 January 2019
Accepted: 6 March 2019
First Online: 15 April 2019
Ethics approval and consent to participate
: The study was approved by the ethics committee of the Charité-Universitätsmedizin Berlin (EA1/190/14). Written informed consent was obtained from the residents themselves or their legal representatives prior any study procedure. This study is registered at ExternalRef removed.
: Not applicable.
: The authors declare that they have no competing interests.
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