Ten trials (79,494 participants) were included. Of these, 9 trials (69,139 participants) met the inclusion criteria. The remaining trial (10,355 participants) was considered a large and important study but it was not placebo-controlled; it was only included in some of the analyses.
Heterogeneity was not significant when the additional study was included in the analyses for non-cardiovascular mortality and for stroke, so this study was included in these analyses. However, heterogeneity was significant for the outcomes of coronary events and for all-cause mortality, so this study was not included in these analyses.
Coronary events (9 studies): statins reduced coronary events (RRR 0.73, 95% CI: 0.70, 0.77).
Mortality (9 studies): statins reduced all-cause mortality (RRR 0.85, 95% CI: 0.79, 0.92). There was no significant change in non-cardiovascular mortality (10 studies; RRR 0.96, 95% CI: 0.90, 1.03).
Stroke (8 studies): statins reduced the incidence of stroke (RRR 0.82, 95% CI: 0.75, 0.90).
When the additional study was included in analyses for coronary events and for mortality, the effect of statins was still beneficial.
There was no evidence of a difference in benefit from statins for men or women (P=0.37), or for hypertensives or normotensives (P=0.15). Although the data were limited, both diabetics and non-diabetics benefited from statins. Smokers appeared to benefit more than non-smokers (P=0.048).
Five studies used pravastatin. For coronary events and mortality the effects of pravastatin and other statins were similar. However, for stroke, the reduction with pravastatin was about half of that of other statins (P=0.039).