Cost-effectiveness of dabigatran compared with warfarin for stroke prevention in atrial fibrillation.

Abstract

BACKGROUND:

Warfarin reduces the risk for ischemic stroke in patients with atrial fibrillation (AF) but increases the risk for hemorrhage. Dabigatran is a fixed-dose, oral direct thrombin inhibitor with similar or reduced rates of ischemic stroke and intracranial hemorrhage in patients with AF compared with those of warfarin.

OBJECTIVE:

To estimate the quality-adjusted survival, costs, and cost-effectiveness of dabigatran compared with adjusted-dose warfarin for preventing ischemic stroke in patients 65 years or older with nonvalvular AF.

DESIGN:

Markov decision model.

DATA SOURCES:

The RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial and other published studies of anticoagulation. The cost of dabigatran was estimated on the basis of pricing in the United Kingdom.

TARGET POPULATION:

Patients aged 65 years or older with nonvalvular AF and risk factors for stroke (CHADS₂ score ≥1 or equivalent) and no contraindications to anticoagulation.

TIME HORIZON:

Lifetime.

PERSPECTIVE:

Societal.

INTERVENTION:

Warfarin anticoagulation (target international normalized ratio, 2.0 to 3.0); dabigatran, 110 mg twice daily (low dose); and dabigatran, 150 mg twice daily (high dose).

OUTCOME MEASURES:

Quality-adjusted life-years (QALYs), costs (in 2008 U.S. dollars), and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS:

The quality-adjusted life expectancy was 10.28 QALYs with warfarin, 10.70 QALYs with low-dose dabigatran, and 10.84 QALYs with high-dose dabigatran. Total costs were $143 193 for warfarin, $164 576 for low-dose dabigatran, and $168 398 for high-dose dabigatran. The incremental cost-effectiveness ratios compared with warfarin were $51 229 per QALY for low-dose dabigatran and $45 372 per QALY for high-dose dabigatran.

RESULTS OF SENSITIVITY ANALYSIS:

The model was sensitive to the cost of dabigatran but was relatively insensitive to other model inputs. The incremental cost-effectiveness ratio increased to $50 000 per QALY at a cost of $13.70 per day for high-dose dabigatran but remained less than $85 000 per QALY over the full range of model inputs evaluated. The cost-effectiveness of high-dose dabigatran improved with increasing risk for stroke and intracranial hemorrhage.

LIMITATION:

Event rates were largely derived from a single randomized clinical trial and extrapolated to a 35-year time frame from clinical trials with approximately 2-year follow-up.

CONCLUSION:

In patients aged 65 years or older with nonvalvular AF at increased risk for stroke (CHADS₂ score ≥1 or equivalent), dabigatran may be a cost-effective alternative to warfarin depending on pricing in the United States.

PRIMARY FUNDING SOURCE:

American Heart Association and Veterans Affairs Health Services Research & Development Service.

• Authors: James V Freeman, Ruo P Zhu, Douglas K Owens, Alan M Garber, David W Hutton, Alan S Go, Paul J Wang, Mintu P Turakhia
• Journal: Annals of internal medicine (Ann Intern Med) Vol. 154 Issue 1 Pg. 1-11 (Jan 04 2011) ISSN: 1539-3704 [Electronic] United States
• PMID: 21041570 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Anticoagulants
• Benzimidazoles
• Fibrinolytic Agents
• beta-Alanine
• Warfarin
• Dabigatran

Topics

• Aged
• Aged, 80 and over
• Anticoagulants (administration & dosage, adverse effects, economics)
• Atrial Fibrillation (complications)
• Benzimidazoles (administration & dosage, adverse effects, economics)
• Cost-Benefit Analysis
• Dabigatran
• Fibrinolytic Agents (administration & dosage, adverse effects, economics)
• Hemorrhage (chemically induced)
• Humans
• Intracranial Hemorrhages (chemically induced)
• Ischemic Attack, Transient (prevention & control)
• Markov Chains
• Myocardial Infarction (chemically induced)
• Quality-Adjusted Life Years
• Risk Factors
• Sensitivity and Specificity
• Stroke (prevention & control)
• Warfarin (administration & dosage, adverse effects, economics)
• beta-Alanine (administration & dosage, adverse effects, analogs & derivatives, economics)