摘要：Objective. To determine if anticoagulant therapy with the
new direct thrombin inhibitor dabigatran is cost-effective
compared with warfarin in elderly patients with atrial fibrillation.
Design. Markov design, cost-effectiveness model using
data from the Randomized Evaluation of Long-Term
Anticoagulation Therapy (RE-LY) trial and other studies
of anticoagulation for atrial fibrillation. Two doses of
dabigatran (low dose, 110 mg twice daily; high dose, 150
mg twice daily) were compared with warfarin. Sensitivity
analyses compared variations in costs of dabigatran, age,
differential risk for ischemic stroke, intracranial hemorrhage,
and myocardial infarction, and utility (quality of
life estimates).
Setting and participants. Modeling conducted for patients
65 years and older with atrial fibrillation not caused by
valvular disease and without contraindications to anticoagulation.
Main outcome measures. Quality-adjusted life-years
(QALYs), costs, and incremental cost-effectiveness ratios,
which compare the cost per change in QALY compared
with the standard treatment, which in this study was warfarin.
Main results. The estimated quality-adjusted life expectancy
was 10.28 QALYs with warfarin, 10.70 QALYs with low-dose
dabigatran, and 10.84 QALYs for high-dose dabigatran. The
incremental cost-effectiveness (ICE) ratios of dabigatran versus
warfarin were $51,229 per QALY for low-dose dabigatran
and $45,372 per QALY for high-dose dabigatran. Sensitivity
analyses demonstrated that the ICE ratio increased with
rising estimated costs of dabigatran but the ICE ratio was
relatively stable with varying other factors, such as age, utility,
and risk of ischemic stroke, intracranial hemorrhage, or
myocardial infarction. In sensitivity analyses simulations,
comparing all variations of factors simultaneously, high-dose
dabigatran was cost-effective in 53% of simulations and
low-dose dabigatran in less than 30% of simulations, if the
cost-effectiveness level was set at $50,000 per QALY. Either
high-dose or low-dose dabigatran was favored over warfarin
in 80% of cases for a cost-effectiveness level of $50,000 per
QALY (high-dose favored in roughly 55% of cases, lowdose
in roughly 25% of cases). When comparing preferred
conditions for each of the therapies, warfarin was superior
for patients with low risk for intracranial hemorrhage, lowdose
dabigatran for patients at moderate to high risk for
intracranial hemorrhage and low risk for ischemic stroke,
and high-dose dabigatran for patients with moderate to high
risk for intracranial hemorrhage and moderate to high risk
for ischemic stroke.
Conclusion. Dabigatran is a cost-effective alternative to warfarin
for elderly patients with atrial fibrillation, especially
for those at moderate to high risk for ischemic stroke and
intracranial hemorrhage.
