Estimated first-year costs of prostaglandin analogs with/without adjunctive therapy for glaucoma management: A United States perspective

Objective: To evaluate costs associated with prostaglandin analogs among newly-diagnosed glaucoma patients in a managed-care population. Research design and methods: A cost minimization model compared annual costs for patients initiating therapy with one of the three prostaglandin analogs (bimatoprost, latanoprost, travoprost). The study cohort was identified from pharmacy claims and eligibility files of patients who met study inclusion criteria. Annual costs were estimated for patients initiating therapy with each prostaglandin based on treatment patterns and medication use over the year. Costs for outpatient physician visits and medications were estimated from standard sources. Results: A total of 4444 patients met study criteria: 674 received travoprost, 729 received bimatoprost, and 3041 received latanoprost. More than 80% stayed on monotherapy for 1 year (82.9% of travoprost patients, 82.8% of bimatoprost patients, and 80.5% of latanoprost patients). Of those who required adjunctive therapy, the average number of days until starting adjunctive therapy was 130 days for travoprost patients, 94 days for bimatoprost patients, and 104 days for latanoprost patients. Average annual costs were $1198, $1290, and $1217 for patients treated with travoprost, bimatoprost, and latanoprost, respectively. Conclusions: The use of adjunctive therapy in glaucoma is an important driver of glaucoma management costs. This study demonstrates that the longer duration of monotherapy and the likelihood to use single rather than combination adjunctive agents contribute to lower annual costs among patients starting on travoprost compared with the other available prostaglandin analogs. Study limitations include the lack of clinical indicators in the study database; further, results may not be generalizable to patients who discontinue prostaglandin analogs or to the population of patients with glaucoma as a whole. Future studies with clinical and compliance indicators would further identity distinctions among treatment regimens.