A net clinical benefit analysis of warfarin and aspirin on stroke in patients with atrial fibrillation: a nested case–control study

Table 3 Net clinical benefit of warfarin, stratified according to anticoagulation intensity, and aspirin

	Adjusted RD*†		Net clinical benefit (strokes prevented per 100 persons/year) (95 % CI)
	Ischemic stroke ǂ	Intracranial hemorrhage ǂ	Weight = 1	Weight = 1.5	Weight = 2
Current use of warfarin monotherapy	0.70 (0.58, 0.82)	0.07 (0.00, 0.15)	0.63 (0.49, 0.77)	0.59 (0.45, 0.73)	0.56 (0.41, 0.70)
Below therapeutic range (INR: <2)	0.14 (−0.30, 0.58)	0.04 (−0.09, 0.17)	0.10 (−0.36, 0.56)	0.08 (−0.38, 0.54)	0.06 (−0.40, 0.52)
Within therapeutic range (INR: 2–3)	0.62 (0.38, 0.86)	0.03 (−0.06, 0.13)	0.59 (0.33, 0.85)	0.57 (0.31, 0.83)	0.56 (0.30, 0.81)
Above therapeutic range (INR: >3)	0.36 (−0.14, 0.86)	0.56 (0.16, 0.96)	−0.20 (−0.84, 0.44)	−0.49 (−1.13, 0.15)	−0.77 (−1.41, -0.13)
Unknown therapeutic range	0.76 (0.64, 0.88)	0.07 (−0.01, 0.15)	0.69 (0.54, 0.83)	0.65 (0.51, 0.80)	0.62 (0.47, 0.76)
Current use of aspirin monotherapy	−0.10 (−0.24, 0.04)	−0.02 (−0.07, 0.03)	−0.08 (−0.23, 0.07)	−0.07 (−0.22, 0.08)	−0.06 (−0.21, 0.09)

Abbreviations: RD: Rate difference; CI: Confidence interval; INR: International normalized ratio.
* Per 100 persons per year.
† Adjusted for excessive alcohol use, smoking status, obesity, peripheral artery disease, myocardial infarction, previous cancer, prior bleeds, thromboembolic disorders, ACE inhibitor use, angiotensin receptor blocker use, antidepressant use, antipsychotic use, NSAID use, and statin use. The stroke model was additionally adjusted for CHADS₂ score, while the intracranial hemorrhage model was additionally adjusted for the components of that score.
\ǂ RDs for ischemic stroke calculated as the rate when off versus on therapy, while the RDs for intracranial hemorrhage calculated as the rate when on versus off therapy.

ISSN: 1471-2261