Original article
Management of Ocular Hypertension: A Cost-effectiveness Approach From the Ocular Hypertension Treatment Study

https://doi.org/10.1016/j.ajo.2006.01.019Get rights and content

Purpose

The Ocular Hypertension Treatment Study (OHTS) demonstrated that medical treatment of people with intraocular pressure (IOP) of ≥24 mm Hg reduces the risk of the development of primary open-angle glaucoma (POAG) by 60%. There is no consensus on which people with ocular hypertension would benefit from treatment.

Design

Cost-utility analysis with the use of a Markov model.

Methods

We modeled a hypothetic cohort of people with IOP of ≥24 mm Hg. Four treatment thresholds were considered: (1) Treat no one; (2) treat people with a ≥5% annual risk of the development of POAG; (3) treat people with a ≥2% annual risk of the development of POAG, and (4) treat everyone. The incremental cost-effectiveness ratio was evaluated.

Results

The incremental cost-effectiveness ratios for treatment of people with ocular hypertension were $3670 per quality adjusted life-year (QALY) for the Treat ≥5% threshold and $42,430/QALY for the Treat ≥2% threshold. “Treat everyone” cost more and was less effective than other options. Assuming a cost-effectiveness threshold of $50,000 to 100,000/QALY, the Treat ≥2% threshold would result in the most net health benefit. The decision was sensitive to the incidence of POAG without treatment, treatment effectiveness, and the utility loss because of POAG.

Conclusion

Although the treatment of individual patients is largely dependent on their attitude toward the risk of disease progression and blindness, the treatment of those patients with IOP of ≥24 mm Hg and a ≥2% annual risk of the development of glaucoma is likely to be cost-effective. Delay of treatment for all people with ocular hypertension until glaucoma-related symptoms are present appears to be unnecessarily conservative.

Section snippets

Methods

We constructed a Markov decision model to compare the cost and effectiveness of treating ocular hypertension over a lifetime. Parameters in the model included estimates of the risk of POAG among those patients for whom pressure lowering medication were prescribed and those patients for whom they were not, the probability of progression of POAG to unilateral blindness, the probability of bilateral blindness among patients with unilateral blindness, and estimates of the impact of POAG and

Results

The cost-effectiveness of treatment of ocular hypertension at each treatment threshold is shown in Figure 2. Each point represents the combination of expected lifetime cost (on the vertical axis) and QALYs gained (on the horizontal axis) that are associated with each treatment threshold: “Treat no one,” “Treat ≥5%,” “Treat ≥2%,” and “Treat everyone.” In Table 3, the thresholds are ranked according to the expected lifetime cost of treatment/person, with “Treat no one” the least expensive and

Discussion

A clinical management strategy that targets a 20% reduction in IOP in people with ocular hypertension has been shown to delay or prevent the onset of glaucoma.8 However, many clinicians continue to maintain that treatment of ocular hypertension is not warranted.9, 37 We have shown that the treatment of people with the highest risk (that is, an annual risk of ≥5% or a five-year risk in excess of 25%; at least 10% of people with IOP of ≥24 mm Hg in the OHTS sample) is highly cost-effective at a

Steven M. Kymes, PhD, is a Research Assistant Professor in the Department of Ophthalmology and Visual Sciences at Washington University in St Louis, Missouri. Dr Kymes is an Assistant Director of the Vision Research Coordinating Center. Before entering academic life, Dr Kymes held various management and marketing positions with health care and managed care organizations. Dr Kymes’ research interests concern cost-effectiveness of medical treatment and testing, assessment of health-related

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    Steven M. Kymes, PhD, is a Research Assistant Professor in the Department of Ophthalmology and Visual Sciences at Washington University in St Louis, Missouri. Dr Kymes is an Assistant Director of the Vision Research Coordinating Center. Before entering academic life, Dr Kymes held various management and marketing positions with health care and managed care organizations. Dr Kymes’ research interests concern cost-effectiveness of medical treatment and testing, assessment of health-related quality of life, and the relationship between insurance plan design and health outcomes.

    Mae O. Gordon, PhD, is a Professor in the Department of Ophthalmology and Visual Sciences at Washington University in St Louis, Missouri. Dr Gordon is the Director of the Vision Research Coordinating Center at Washington University and is Co-Chairman of the Ocular Hypertension Treatment Study. Among her areas of research are clinical trial design, assessment of quality of life, and persistency in treatment of glaucoma.

    Supplemental Material available at AJO.com.

    Supported by Awards to the Washington University School of Medicine Department of Ophthalmology and Visual Sciences from the National Eye Institute, the National Center on Minority Health and Health Disparities, National Institutes of Health (grants EY09341 and EY09307), and unrestricted grants from Merck Research Laboratories and Pfizer, Inc; and by Awards to the Washington University Department of Ophthalmology and Visual Sciences from Research to Prevent Blindness, Inc, and the National Institutes of Health (P30 EY 02687) Core grant.

    For a complete list of OHTS investigators, please see the OHTS website at https://vrcc.wustl.edu

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