Best tool to appraise the internal validity of a systematic review or meta-analysis We are conducting an evidence base synthesis for a major European cardiovascular assocation.
We plan to search, appraise and summarize systematic reviews and meta-analyses on our topic of choice, inasmuch as we would do when performing an umbrella review.
A key methodological question is: how to appraise the internal validity of selected systematic reviews?
Is AMSTAR the best tool, in terms of internal validity and consistency, or are there other tools with better features?

I have seen a couple of tools in practice in health research (I'm only just about to start using these myself, so can only point out some options rather than comment on choice).

*

*AMSTAR (A MeaSurement Tool to Assess systematic Reviews)


*ROBIS (Risk of Bias in Systematic Reviews)
It looks like there are some published appraisals as to how these tools work, though these seem to concentrate more on reliability measures than the validity of the tool (i.e. the validity of the tool for assessing the validity of systematic reviews!)
Here is a 2020 open-access publication by Gates et al. in the Journal of Clinical Epidemiology (this particular article is open-access even though the journal as a whole is not).
