>"I'm going to suggest if you're facing death from an AIDS-related illness, a relative risk of 2.00 vs. 1.87 will feel very, very similar to you." I at first t

>"I'm going to suggest if you're facing death from an AIDS-related illness, a relative risk of 2.00 vs. 1.87 will feel very, very similar to you." I at first thought we both understood there would be some uncertainty about these values no matter what but we were leaving that out out for simplicity's sake. Roughly, I was assuming it is at least +/- 10-20%. The reason these values "feel very, very similar" is that I would not expect medical data to be able to distinguish between them. >"Define "stable" - because even if the effect of something is fixed in the same way a physical constant it, it's invariable sampled with error." Ok... so you are implicitly considering uncertainty. >"Again, if I give you five studies that suggest that HAART improves survival by: 100%, 102%, 87%, 94% and 96% are you really going to suggest that we don't know that HAART improves survival?" Not enough info. - Where did the uncertainty go? - What methods were used to generate these values? Even basic strategies like blinding the people collecting/processing/analyzing data is often still missing. - What population/frame do those numbers refer to, and how much error can we expect from extrapolating for other situations in the future? You need a reliable quantification, doing this hand wavy "things are better/worse, significant/insignificant" is an awful idea.