Footnotes

• Twitter @carlheneghan, @@DrJackOSullivan, @krmahtani

• Contributors CH wrote the first draft, JO and KRM contributed to further drafts and all authors approved the final version.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests CH is supported by the NIHR School for Primary Care Research. Evidence Synthesis Working group (NIHR SPCR ESWG project 390). CH isalso supported by the NIHR Oxford Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, an NIHR senior investigator and editor-in-chief of BMJ Evidence-Based Medicine. JO is an NIH Postdoctoral Fellow at Stanford University. He is an associate editor at BMJ Evidence-Based Medicine. KRM is supported by the NIHR School for Primary Care ResearchEvidence Synthesis Working group (NIHR SPCR ESWG project 390).

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.