Clinical and economic impact of new trends in glaucoma treatment.

CONTEXT

Glaucoma is a chronic ophthalmic condition affecting approximately 15 million people. Several therapies are currently available (eg, beta-blockers, sympathomimetics, carbonic anhydrase inhibitors) but have side effects that may limit use. Over the last few years, new medications with improved efficacy and side-effect profiles have become available. This analysis evaluates 2 therapies, brimonidine and betaxolol, based on head-to-head clinical trial data to determine clinical consequences and their related expected costs.

OBJECTIVE

To calculate comparative costs and the cost-effectiveness of brimonidine 0.2% and betaxolol 0.25% as first-line therapy for patients with primary open-angle glaucoma.

DESIGN

Safety, efficacy, effectiveness, and quality-of-life data were collected in a multicenter, randomized, double-blind, head-to-head comparative effectiveness study, with a drug switch possibility. A disease-intervention model (decision tree) was developed with clinicians, academicians, and health economists. Components of care for each pathway in the model were identified and evaluated; their costs were applied at appropriate points throughout the tree. Expected outcomes and costs were computed and compared.

PATIENTS

Participants were men (n = 76) and women (n = 112), 21 years of age or older, with newly diagnosed or currently untreated ocular hypertension or open-angle glaucoma.

RESULTS

The clinical success rates of first-line brimonidine 0.2% and betaxolol 0.25% are 73.9% and 56.2%, respectively, as determined in a head-to-head comparative effectiveness trial. Total expected costs for patients receiving brimonidine and betaxolol as a primary therapy are $301.37 and $328.19, respectively, based on the model. Dividing costs by outcomes, the cost-effectiveness ratios for brimonidine and betaxolol are $407.81 ($301.37/0.739) and $583.97 ($328.19/0.562), respectively, representing the cost/unit outcome, or the cost to achieve clinical success.

CONCLUSIONS

Brimonidine 0.2% is less costly and more cost-effective than betaxolol 0.25% when used as initial monotherapy with and without subsequent add-on therapies, including laser treatments and/or surgery, as needed.