Text and Data Mining valid from 2018-10-31
Received: 28 March 2018
Accepted: 19 October 2018
First Online: 31 October 2018
Ethics approval and consent to participate
: As this work is an overview of existing systematic reviews and uses secondary anonymised data without access to individual identifiers, approval and consent to participate was not required.
: Not applicable.
: As manager of SNUG, Leanna Wakely is a contributor to the research and represents the charity which supports this research. The remaining authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.