COST-EFFECTIVENESS ANALYSIS FOR ONYCHOMYCOSIS THERAPY IN CANADA FROM A GOVERNMENT PERSPECTIVE

An economic analysis of the oral antifungal drugs griseofulvin (GRI), ketoconazole (KET), and terbinafine (TER), currently registered and used in treating onychomycosis of fingernails and toenails, was performed using a model that incorporates elements of both meta-analysis and pharmacoeconomics. The meta-analysis of published studies determined rates of success, relapse and side-effects. The perspective taken for the analysis was that of the government payer, with expected total cost and cost-effectiveness being calculated. A multiphase approach was used. The studies of onychomycosis of the fingernails showed that TER had a 95.0% success rate, KET 80.9%, and GRI 59.6%. GRI had the lowest acquisition costs. The success rates for onychomycosis of the toenails were: TER 78.3%, KET 40.8%, and GRI 17.5%. GRI had the lowest acquisition costs. However, expected cost comparison showed TER had the lowest cost because of shorter treatment duration. The expected cost of therapy with a 100% government payer perspective for fingernail onychomycosis was the lowest for TER ($439.83), followed by GRI ($480.80), then KET ($755.46). Toenail onychomycosis showed the same order for the comparators, with TER $1049.77, GRI $1388.54 and KET $1936.48. When compared with TER, fingernail cost-effectiveness ratios for GRI and KET were 1.51 and 2.00. Toenail cost-effectiveness ratios were 2.49 and 2.48, respectively. For both fingernail and toenail onychomycosis, TER had the greatest number of disease-free days (973 for fingernails; 1073 for toenails), followed by KET (837; 798), then GRI (702; 569). The drug which had the lowest expected cost, and cost per disease-free day, was TER; it was also shown to be the most cost-effective choice for onychomycosis of both fingernails and toenails, with a shorter treatment time, better success rate, the greatest amount of disease-free days, and better financial outcomes than other study comparators.