A comment on the statistics:

The meaning of "80% power to show statistical signficance if the underlying effect is 30% RRR" is a little tricky to explain, but I'll give it a try...

Consider this: If you flip a coin 10 times and get 4 heads and 6 tails (= the "observation"), would you then claim that the coin is not fair? No, of course not, you are obviously not guaranteed to always hit the average (which would be 5 heads and 5 tails, of course). The underlying probabiliy of getting heads is 50%, but you are not guaranteed to get a result with 50% heads. Same thing with the BETonMACE study, the assumption is that the RRR would be 30%, but even if that is true (could be tested in a very, very, very large study), that may not what the actual results show - there may appear to be a lower (or greater) RRR. The 80% power refers to the chance of hitting statistical significance (a calculation that is based on the observed BETonMACE data) if the underlying effect is 30%. That means that even if the effect is observed to be lower than 30%, BETonMACE may still hit statistical significance.

I would expect - roughly - that a 24% RRR would be borderline for showing a statistically signficant effect. 

BR.

BKC