22:32 Oct 10 

In fact, I wasn't trying to "have it both ways". The point is that "varying levels of" tends to sound formal rather than colloquial. Some people had given opinions that "more or less" was awkward, I just wanted to see whether a formal publication with a high editorial standard would use it and the answer was "yes, frequently". Of course doctors do sometimes like to sound a casual note to relieve their occupational stress (it makes them sound reassuring in a funny sort of way). I would find something like "you will more or less survive this infection" a touch too casual.

17:38 Oct 9 

Barbara, You surely can't have it both ways! First you claim this is an informal text, then you compare it with the BMJ - which is anything but informal

14:38 Oct 9 

Just to see what a serious body like the BMJ thought about this, I tried googling '"more or less severe" bmj' and got 36.700 ghits.
e.g.
"Some combinations are benign; others result in more or less severe forms of cystic fibrosis. "
bmj.bmjjournals.com/cgi/content/full/312/7025/196 -

"a more or less severe degree of asthma (expressed as the baseline FEV1 and concentration provoking a fall in FEV1 of 20% or more (PC20))."
thorax.bmj.com/cgi/content/full/54/1/15 -

14:28 Oct 9 

I know what you're getting at Barbara, but I think that that sense (the casual sense) of "more or less" rather ignores "important" - which needs to be taken into account (décalage plus ou moins important)

13:48 Oct 9 

In reply to the people who think this phrase sounds clumsy or awkward, I suggest that you are not paying attention to register. I certainly would avoid it in a formal context, but the text quoted by the Asker did not seem very formal in register and a colloquial expression seemed to fit.