Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
The letter by Kaufmann1 is quite reassuring as it demonstrates that policy researchers have intuitively and astutely questioned simple evidence hierarchies and were sceptical about using study design or study label as a surrogate for validity. This was the impetus for proposing our revised pyramid.
The letter also reminds us that there are higher order scientific publications (guidelines and …
Contributors MHM drafted the letter. FA and MA contributed to and approved the final manuscript.
Competing interests None declared.
Provenance and peer review Not commissioned; internally peer reviewed.