Dr.ObesityMed said:The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.
That is right for the common case. Whether it is right for the case being asked about depends on a detail that has not been given.
OP back with an update, since a thread like this is useless without one.
Closing this out. What actually changed my mind was the point about waiting for a trend instead of reading a single measurement, which is embarrassing in hindsight and worth saying anyway.
Adding the clinical framing, because it changes how the question reads. It is worth asking what the claim would look like if it were false. If nothing would look different, it is not a claim about the world and no amount of discussion will settle it.
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Shop Reference Standardsjames_edin said:It is worth asking what the claim would look like if it were false.
Adding a me-too, because a thread of one person's experience is not much use. Posting only so the count is not one.
james_edin said:It is worth asking what the claim would look like if it were false.
Coming at james_edin’s question from a different direction. 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.