Received: 19 October 2017
Accepted: 22 January 2018
First Online: 13 February 2018
Ethics approval and consent to participate
: Not applicable (not needed as per local regulations, since data were anonymized and extracted retrospectively from clinical charts).A copy of the written consent of the patients’ parents is included in the hospital documentation of the patients.
: The authors declare that they have have no competing interests.
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