Updates are available Correction dated 2018-08-01

Article History

Received: 19 January 2018

Revised: 21 February 2018

Accepted: 22 February 2018

First Online: 28 May 2018

Change Date: 1 August 2018

Change Type: Correction

Change Details: The original version of this article, published on 28 May 2018, unfortunately contained a mistake.

Compliance with ethical standards

:

: The scientific guarantor of this publication is Sebastian Schindera.

: 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.

: No complex statistical methods were necessary for this paper.

: Institutional Review Board approval was not required because no patient data were analysed.

: Written informed consent was not required for this study because no patient data were analysed.

: • retrospective• cross-sectional study• multicentre study