Cost-effectiveness of Vitamin Therapy for Age-Related Macular Degeneration
Received 2 May 2006; accepted 26 October 2006. published online 23 February 2007.
Objective
To determine the cost-effectiveness of vitamin therapy (antioxidants plus zinc) for all indicated patients diagnosed with age-related macular degeneration (AMD).
Design
We compared the impacts of vitamin therapy with those of no vitamin therapy using a computerized, stochastic, agent-based model. The model simulated the natural history of AMD and patterns of ophthalmic service use in the United States in a cohort from age 50 years until 100 or death.
Participants and/or Controls
The model created 20 million simulated individuals. These individuals each received both the intervention (vitamin therapy after diagnosis) and the control (no vitamin therapy). Expected outcomes generated when vitamins were taken after diagnosis were compared with the expected outcomes generated when they were not.
Methods
The model created individuals representative of patients in the U.S. Incidence of early AMD was based on published studies, as was vision loss and response to choroidal neovascularization therapies. Post–incident disease progression was governed by previously unpublished data drawn from the Age-Related Eye Disease Study.
Main Outcome Measures
Extent of disease progression, years and severity of visual impairment, cost of ophthalmic care and nursing home services, and quality-adjusted life years (QALYs). Costs and benefits were considered from the health care perspective and discounted using a 3% rate. The analysis was run for 50 years starting in 2003.
Results
Compared with no therapy, vitamin therapy yielded a cost-effectiveness ratio of $21 387 per QALY gained and lowered the percentage of patients with AMD who ever developed visual impairment in the better-seeing eye from 7.0% to 5.6%.
Conclusions
Our model demonstrates that vitamin therapy for AMD improves quality of life at a reasonable cost.
1RTI International, Research Triangle Park, North Carolina.
2Division of Diabetes Translation, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia.
Correspondence and reprint requests to David B. Rein, PhD, RTI International, 2957 Flowers Road, Suite 119, Atlanta, GA 30341.
Manuscript no. 2006-502.
Funding for this research was provided by the Division of Diabetes Translation, Centers for Disease Control and Prevention (contract no. 200-2002-00776).
ABSTRACT