Text and Data Mining valid from 2019-08-16
Received: 14 May 2018
Accepted: 7 August 2019
First Online: 16 August 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Commission of the Greifswald Medical Faculty (BB 119/11, 30.11.2011). Approval and declarations of consent are available at the Medical Faculty Greifswald.
: All authors have read and accepted the final manuscript and agreed to its publication.
: The authors declare that they have no competing interests.