Text and Data Mining valid from 2019-10-25
Received: 22 September 2019
Accepted: 4 October 2019
First Online: 25 October 2019
Compliance with ethical standards
: On behalf of all authors, the corresponding author states that there are no conflicts of interest.
: The study has been approved by the hospital’s ethics committee and has, therefore, been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.