Five RCTs (n=79,624 patients; 56,091 men and 23,533 women) were included. Sample sizes ranged from 2,116 to 45,852 patients. Allocation sequence generation, randomisation, and blinding were adequate in all five trials. The duration of follow-up ranged from two weeks to 35 months and follow-up was more than 99% complete in all trials.
Major cardiovascular events: Compared with placebo, clopidogrel did not significantly reduce the rate of major cardiovascular events for women, but did for men (OR 0.84, 95% CI 0.78 to 0.91).
Mortality: Compared with placebo, clopidogrel significantly reduced the all-cause mortality in men (OR 0.91, 95% CI 0.84 to 0.97), but not in women (OR 0.99, 95% CI 0.90 to 1.08). No statistically significant difference was found in the cardiovascular mortality for both women and men.
Myocardial infarctions: Compared with placebo, clopidogrel significantly reduced myocardial infarctions for both women (OR 0.81, 95% CI 0.70 to 0.93) and men (OR 0.83, 95% CI 0.76 to 0.92).
Strokes: Compared with placebo, clopidogrel did not significantly reduce the risk of stroke (ischaemic or haemorrhagic) for women, but reduced the risk for men (OR 0.83, 95% CI 0.71 to 0.96). Clopidogrel also reduced the risk of ischaemic stroke for men (OR 0.84, 95% CI 0.71 to 0.99), but not haemorrhagic stroke.
Major bleeding: Compared with placebo, clopidogrel was associated with an increased risk of major bleeding for both women (OR 1.43, 95% CI 1.15 to 1.79) and men (OR 1.22, 95% CI 1.05 to 1.42).
The results of the subgroup analyses were reported and no evidence of heterogeneity was found for any outcome.