Are cost benefits of anticoagulation for stroke prevention in atrial fibrillation underestimated?
OBJECTIVE
Stroke outcomes in patients with atrial fibrillation (AF) tend to be worse than those in patients without AF. The objective of this study was to evaluate whether the cost benefits of anticoagulation for stroke prevention in AF may currently be underestimated by existing economic models that do not distinguish between different stroke outcomes.


METHODS
A literature review was conducted in 3 areas: (1) studies comparing stroke outcomes in AF and non-AF patients; (2) studies providing long-term cost of stroke estimates; and (3) studies modeling the cost-effectiveness of anticoagulation with a vitamin K antagonist (eg, warfarin) in AF patients.


RESULTS
There is considerable evidence that stroke in AF patients has a worse outcome than in patients without AF, including higher mortality, severity, and recurrence rates, and greater functional impairment and dependency. Estimates of the long-term cost of stroke of different severities were between US 24,991 dollars for a mild stroke over 5 years and US 142,251 dollars for a major ischemic stroke over a lifetime (2004 prices). The cost of a severe ischemic stroke may typically be 3-times that of mild stroke. However, cost-effectiveness models for anticoagulation in patients with AF have used average (not AF-specific) cost-of-stroke data, and most have used stroke severity distributions derived from clinical trials, which may differ from those in clinical practice.


CONCLUSIONS
Existing economic models underestimate the cost benefits of anticoagulation for stroke prevention because they do not adjust for poorer outcomes associated with cardioembolic strokes.
Miller
Paul S J
PS
AstraZeneca, HEOR/Clinical Science, Parklands FE2 D/4, Alderley Park, SK10 4TG UK. Paul.Miller3@astrazeneca.com
Andersson
Fredrik L
FL
Kalra
Lalit
L
D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000191:economics* / Q000494:pharmacology*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D002545:Brain Ischemia / Q000473:pathology; D002561:Cerebrovascular Disorders / Q000188:drug therapy / Q000191:economics; D002986:Clinical Trials as Topic; D003362:Cost-Benefit Analysis; D006801:Humans; D007511:Ischemia / Q000473:pathology; D016239:MEDLINE; D008875:Middle Aged; D008962:Models, Theoretical; D015999:Multivariate Analysis; D019057:Quality-Adjusted Life Years; D012307:Risk Factors; D020521:Stroke / Q000188:drug therapy* / Q000191:economics* / Q000517:prevention & control*; D013997:Time Factors; D016896:Treatment Outcome; D014812:Vitamin K / Q000037:antagonists & inhibitors; D014859:Warfarin / Q000494:pharmacology
D000925:Anticoagulants; D014812:Vitamin K; D014859:Warfarin