Costs and persistence of carbonic anhydrase inhibitor versus alpha-2 agonists, associated with beta-blockers, in glaucoma and ocular hypertension: an analysis of the UK-GPRD database.

OBJECTIVE To compare the effectiveness and associated costs of carbonic anhydrase inhibitors + beta-blocker versus alpha-2 adrenergic agonists + beta-blocker in glaucoma therapy, as documented by The United Kingdom General Practitioner Research Database (UK-GPRD). RESEARCH DESIGN Patient chart analysis. METHODS Patient records were screened for diagnoses of ocular hypertension or glaucoma, and for surgery, laser therapy or medication specific to glaucoma. Selected patients were those prescribed either carbonic anhydrase inhibitors + beta-blocker or alpha-2 adrenergic agonists + beta-blocker. Treatment failure was defined as a glaucoma prescription change, i.e. addition, cessation or replacement of medication, surgery or laser therapy. Times to treatment failure were compared with an adjusted Cox model. MAIN OUTCOME MEASURES Treatment persistence and cost. RESULTS Included patients were those treated with either carbonic anhydrase inhibitors + beta-blocker (n = 5581) or alpha-2 adrenergic agonists + beta-blocker (n = 1164). The average age at diagnosis was 68.1 years and 48.2% were male. Treatment failure at one year was significantly (p < 0.001) less frequent after carbonic anhydrase inhibitors + beta-blocker (57% of patients) than after alpha-2 adrenergic agonists + beta-blocker (64.3%). The hazard ratio for failure was lower (0.82: p < 0.0001) with carbonic anhydrase inhibitors + beta-blocker following adjustment for age, gender, comorbidities and duration of follow-up. Adjusted annual costs of glaucoma management were pound 348.04 for carbonic anhydrase inhibitors + beta-blocker and pound 356.80 for alpha-2 adrenergic agonists + beta-blocker. CONCLUSIONS According to UK-GPRD information, glaucoma therapy with carbonic anhydrase inhibitors + beta-blocker is more persistent than with alpha-2 adrenergic agonists + beta-blocker at a similar cost.