A systematic review 1 including 4 studies with a total of 2,753 subjects was abstracted in DARE. The reported fixed low dose ranged from 0.5 to 3 mg/day. The target International Normalised Ratio (INR) was 1.1 to 1.6 for the low dose and 2 to 3.5 for the adjusted dose. Adjusted-dose warfarin reduced the risk of all thrombotic events compared with low-dose warfarin; the pooled RR was 0.50 (95% CI: 0.25 to 0.97, P=0.041). There was no statistically significant heterogeneity (P=0.56). Adjusted-dose warfarin tended to decrease ischaemic stroke compared with low-dose warfarin. However, this result was not statistically significant (RR 0.46, 95% CI: 0.2 to, 1.07, P=0.071). There was no difference in haemorrhagic death between the two treatments; the RR was 0.97 (95% CI: 0.27 to 3.54). Although mini- dose warfarin tended to reduce the risk of major haemorrhage, this was not statistically significant (RR 1.23, 95% CI: 0.67 to, 2.27, P=0.51).
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