Text and Data Mining valid from 2019-10-12
Received: 17 July 2019
Accepted: 30 September 2019
First Online: 12 October 2019
Compliance with ethical standards
: The authors declare that they have no competing interests.
: This article does not contain any studies with human participants or animals performed by any of the authors. Ethical approval was not applicable for this systematic review and meta-analysis.
: Informed consent was obtained from all individual participants included in the study.