Cost-utility analysis of botulinum toxin type A versus oral drug treatment in patients with severe blepharospasm in Thailand

Background: Blepharospasm is a chronic facial movement disorder affecting a person’s ability to work, causing depression, pain, and a reduced quality of life (QoL). Botulinum toxin type A (BoNT-A) treatment can improve these conditions; however, its cost remains a significant barrier for inclusion of this indication into the Thai National List of Essential Medicine. Objectives: This study aimed to assess the cost-effectiveness of onabotulinumtoxinA (onaBoNT-A) and abobotulinumtoxinA (aboBoNT-A) treatment compared to oral medication treatment in patients with severe blepharospasm from a societal perspective. Methods: A cost-utility analysis using a two-part model was conducted to analyze lifetime costs and quality-adjusted life-years (QALYs). Inputs were mainly obtained from real-world evidence of 159 Thai patients with blepharospasm. Costs and outcomes were discounted at 3% annually and presented as 2023 value. Incremental cost-effectiveness ratios (ICERs) were estimated. Deterministic and probabilistic sensitivity analyses were also conducted. Results: In comparison to standard oral medication, both onaBoNT-A and aboBoNT-A incurred greater lifetime cost (3,055 USD, 2,889 USD vs 1,926 USD) while gaining additional QALYs (6.94 years, 6.94 years vs 6.53 years). The estimated ICERs were 2,722 USD/QALY for onaBoNT-A and 2,323 USD/QALY for aboBoNT-A. Utility and cost of BoNT-A were important determinants in the sensitivity analysis. Conclusion: Among patients with severe blepharospasm, both onaBoNT-A and aboBoNT-A were considered a cost-effective strategy under the Thai willingness to pay threshold of 4,613 USD/QALY. Having aboBoNT-A was slightly more favorable due to lower cost, using a conversion ratio of 1U of onaBoNT-A: 3U of aboBoNT-A.