Cochrane has done an analysis of clinical trials looking at the effects of statins. Cochrane is an independent consortium which does meta-analyses of clinical trials, in effect combining them as "one big trial".

Two of the high points are:

(1) All-cause mortality was greater in the placebo compared to the statin group - there were an "extra" 146 deaths in the placebo group. However, there were about 24000 people in each group - this is about a 0.6% increased risk, assuming that statins were the only important factor.

(2) Pooled fatal and non-fatal cardiovascular disease events were greater in the placebo compared to statin group - an "extra" 240 events in the placebo group. There were about 17600 people in each group - this is about a 1.3% increased risk, again assuming that statins were the only important factor.

The above numbers of people in the various clinical trials are different because different trials looked at different things.

I was surprised how weak these effects seem to be so I had a chat to my partner about them. Some time ago she coordinated a large epidemiology project looking at the effects of different forms of contraception on women's health so she knows more than I do about this.

Her comment was that such small effects would have been of marginal interest to her. She drew a contrast - if a woman is over-weight, over 30 and smokes then oral contraception is a bad idea because of significantly increased risk of cardiovascular disease.

The long and very technical Cochrane study is here Statins for the primary prevention of cardiovascular disease - Taylor - 213 - The Cochrane Library - Wiley Online Library.