PharmacoVig_BOS said:

Propensity score matching studies and the trial evidence: when RCTs aren't available for a specific question, propensity score-matched observational…

That is right, and it stops being right at the edges. The general case is well behaved; the interesting cases in this thread are all at the boundary where the general case breaks.

laura_annarbor said:

Bayesian meta-analysis perspective on the trial evidence: traditional frequentist meta-analyses report point estimates and confidence intervals.

Bookmarking. The distinction being drawn above is the one nobody else makes.

PharmacoVig_BOS said:

Propensity score matching studies and the trial evidence: when RCTs aren't available for a specific question, propensity score-matched observational…

I do not accept the framing. The question has been narrowed to the version that has a tidy answer, and the part that was dropped is the part the OP actually asked about.

One concrete data point for the thread. The boring version of this is the one that works, and the boring version is: measure a baseline, change one variable, wait, measure again under the same conditions. Nobody wants that answer and it is still the answer.

Moderator note: reminder that nothing in this thread is medical advice, and that clinical claims need a source.