Text and Data Mining valid from 2019-03-21
Received: 25 November 2018
Accepted: 12 March 2019
First Online: 21 March 2019
Compliance with ethical standards
: The authors declare that there is no conflict of interest.
: Ethical approval and patient consent are not required since this is an overview based on published studies.
: All analyses were based on previously published studies; thus, no informed consent is required.