wendy_avl said:

For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine.

Pushing back on wendy_avl here. The counter-case has not been addressed. Somebody upthread described the situation that does not fit, and the thread moved on rather than engaging with it, which is the failure mode this board is supposed to avoid.

wendy_avl said:

For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine.

Agreed, and the size of the effect matters as much as its existence. Something real and small gets treated here as though it were real and decisive.

Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again.

From the other side of the consultation, briefly. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

Worth separating that from vendor vetting, which this thread keeps folding into the same question. They behave differently and the advice does not transfer.

PharmacoVig_BOS said:

The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.

Adding a me-too, because a thread of one person's experience is not much use.