Adding the clinical framing, because it changes how the question reads. Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the correction. That is slower than asserting, and it is the only version that survives being wrong.

dan_philly said:

One practical note: write down what you did and when, before you need it.

Agreed on the substance. I would put less weight on the timescale, because two months of anything is not enough to distinguish a trend from a wobble.

dan_philly said:

One practical note: write down what you did and when, before you need it.

Thank you — that is the clearest version of this I have read, and I have read a lot of them. I will report back once I have actually tried it.

Adding the clinical framing, because it changes how the question reads. 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.

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