Text and Data Mining valid from 2019-08-29
Received: 21 May 2019
Revised: 4 July 2019
Accepted: 29 July 2019
First Online: 29 August 2019
Compliance with ethical standards
: The scientific guarantor of this publication is Professor Alain Blum.
: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
: One of the authors has significant statistical expertise.
: Written informed consent was waived by the Institutional Review Board.
: Institutional Review Board approval was not required because retrospective studies with fully anonymized patient data do not require ethics committee approval.
: • retrospective• observational• performed at one institution