Cost and effectiveness of brinzolamide versus dorzolamide in current practice: an analysis based on the UK-GPRD database

SUMMARY

This study compared both the costs and effectiveness of brinzolamide and dorzolamide according to data in the United Kingdom General Practitioner Research Database (UK-GPRD). Files of patients with a diagnosis of ocular hypertension or glaucoma who also received topical treatments were extracted. Patients who began dorzolamide or brinzolamide treatment after August 2000 were then selected. Treatment failure was defined as a prescription change (adding or removing a topical treatment), laser treatment or surgery. The time to treatment failure was compared using actuarial methods. The economic viewpoint of the UK National Health Service (NHS) was adopted. The cost of switching was calculated using resource costs for the year 2000. Data on 49,799 glaucoma patients were extracted from the database, of these patients 107 were treated with brinzolamide and 1,005 with dorzolamide. The differences between groups were not statistically significant at the start of treatment. Patients' mean age was 74.3 years, 56% were female and 44% male. Their prescriptions were 24.1% for mono-therapy and 18.3% first-line. Treatment failure at 1 year was experienced by 31% of patients treated with brinzolamide and 45% treated with dorzolamide (p<0.01). The daily cost of glaucoma treatment for patients who switched (failures) was higher (£1.14 per day) than for patients who continued their treatment (£0.88 per day). The mean cost of treating glaucoma with brinzolamide was less (£162.5) than with dorzolamide (£201.4). Brinzolamide not only costs the NHS less than dorzolamide, but patients treated with brinzolamide also experience fewer treatment failures, according to the UK-GPRD, which leads to further cost savings for the NHS.

Keywords: :

• cost
• effectiveness
• glaucoma
• carbonic anhydrase inhibitors