Text and Data Mining valid from 2019-12-01
Received: 1 February 2019
Accepted: 14 October 2019
First Online: 3 December 2019
Ethics approval and consent to participate
: The Ethics Committee at the Medical Chamber of Lower Saxony (Hannover, Germany) granted ethical approval for this research. The study was conducted in accordance with the Declaration of Helsinki. All participants gave their written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.