Funding for this research was provided by:
Bundesministerium für Bildung und Forschung (16PGF0112)
Received: 12 July 2018
Accepted: 15 April 2019
First Online: 1 May 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of the University Medicine of Greifswald, Germany, under the reference number BB026/13. We employed retrospective pseudonymized data, and no written informed consent needed to be obtained from patients according to German data protection laws and common GCP standards.
: Not applicable.
: The authors declare that they have no competing interests.
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