ingrid_STO said:

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

There is a second half to this that has not been said yet. It helps to say which part of this you are uncertain about. A precise question gets a precise answer; a general one gets everybody’s favourite anecdote.

I would rather be corrected than agreed with, if it comes to it.

The figures, for anyone assembling their own picture. Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a trend.

Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again. Report rather than reply if it drifts again.

PeptideChemSF said:

Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a…

I read this differently from PeptideChemSF, on substance rather than tone. I would resist the confidence. Half of what this board was certain about two years ago has since been quietly dropped, and nobody went back to correct the threads.

PeptideChemSF said:

Give anything pharmacological four weeks before you judge it, and give anything measured weekly a four-point rolling average before you call it a…

Right, and the exception is worth naming rather than left implied, because the exception is where people get into trouble.

If somebody has the primary source to hand I would rather cite it than paraphrase it.