Abstract

Volume.124 Number.4

Original article : Clinical science

Evaluation of Pharmacoeconomics of Glaucoma Ophthalmic Drugs Using a Cost-Effectiveness Analysis Model
Tadashi Nakano1, Yoshinori Ito1, Yoshiyuki Shibasaki2
1 Department of Ophthalmology, The Jikei University School of Medicine
2 Medical Affairs, Otsuka Pharmaceutical Co., Ltd.

Purpose: To evaluate pharmacoeconomics of glaucoma medications using a cost-effectiveness analysis model including intraocular-pressure lowering effect, safety, and medical expenditures.
Methods: Using data from phase-III clinical trials of glaucoma medications, such as prostaglandins (latanoprost (LAT), tafluprost (TAF), and bimatoprost (BIM)), carbonic anhydrase inhibitors/β-blockers [azorga (BTFC) and cosopt (DTFC)], and prostaglandins/β-blockers [xalacom (LTFC), tapcom (TTFC), and mikelluna (LCFC)], in Japanese patients with primary open-angle glaucoma or ocular hypertension, we developed a cost-effectiveness analysis model to assess cost-effectiveness. We calculated the incremental cost-effectiveness ratio (ICER) based on the results of simulation using the model and evaluated the variation in each input parameter including medical expenditures using sensibility analysis.
Results: ICER showed negative values in comparisons of BTFC with DTFC, BIM with TAF, TTFC with LTFC, and LCFC with TTFC or LTFC. The strongest influencing factors on ICER were the drug continuation rate and intraocular-pressure reduction rate for 4 weeks for prostaglandins, and the intraocular-pressure reduction rate for 8 weeks for carbonic anhydrase inhibitors/β-blockers and prostaglandins/β-blockers. The probability of cost-effectiveness was not influenced by willingness to pay expenditures, except LAT and BIM.
Conclusions: The new comprehensive evaluation of pharmacoeconomics that includes medical expenditures as well as efficacy and safety for the conventional index of glaucoma medications was feasible. In the evaluation of the present study, BIM (prostaglandin), BTFC (carbonic anhydrase inhibitor/β-blocker), and LCFC (prostaglandin/β-blocker) showed superior cost-effectiveness compared with the same classes of ophthalmic solutions.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 124: 330-343, 2020.

Key words
Glaucoma, Intraocular-pressure lowering effect, Medical expenditure, Incremental cost-effectiveness ratio, Sensibility analysis
Reprint requests to
Tadashi Nakano, M. D., Ph. D. Department of Ophthalmology, The Jikei University School of Medicine. 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan