Received: 11 September 2019
Accepted: 11 May 2020
First Online: 25 May 2020
Change Date: 25 June 2020
Change Type: Correction
Change Details: An amendment to this paper has been published and can be accessed via the original article.
Ethics approval and consent to participate
: All analyses were part of the quality management of LMS. To ensure privacy, the data linkage and appropriate anonymisation procedure was developed with the help of a data protection official. Accordingly, no ethics approval was required (Section 2, University of Lübeck Ethics Commission statute, 2011). The need for consent was waived in accordance with Section 51 of the Federal Data Protection Act that defines consent regulations (BDSG, 2017).
: Not applicable.
: The authors report no competing interest.