Cost-effectiveness of interferon beta-1b in slowing multiple sclerosis disability progression - First estimation

Objective: To estimate the cost-effectiveness (CE) of interferon beta-1b (I FN beta-1b) in slowing disability progression in persons with relapsing-rem itting multiple sclerosis (RRMS). Methods: Treatment program costs and health outcomes are modeled for cohort s of 1,000 females and 1,000 males followed 40 years from onset. Fifteen sc enarios model MS natural history progression, treatment efficacy, direct tr eatment costs, and MS healthcare costs. A single randomized placebo-control led trial of IFN beta-1b found reduced disease activity by MRI, reduced fre quency and severity of exacerbations, and a tendency toward slower disabili ty progression. Disability years avoided are modeled as the primary health outcome analyzed . A ministry of health (MOH) perspective is adopted, using Nova Scotia popu lation-based data. Annual IFN beta-1b direct treatment costs (Can $16,685) are high relative to both MOH healthcare costs per person with MS (Can $2,0 00) and estimated MOH costs avoided. Results: Given "reference case" assumptions for women with RRMS, treatment reduces lifetime disability years by 10%. Cost per disability year avoided before discounting is Can $189,230 (US $124,892), and Can $274,842 (US $181 ,395) after discounting at 5%. Estimates for alternative scenarios vary gre atly, leaving main findings unchanged. Conclusions: Using the Expanded Disability Status Scale, cost per disabilit y year avoided due to interferon beta-lb treatment in RRMS is quite high. C omparable CE estimates. using MS-specific or generic health-related quality -of-life outcome measures, are even higher. Further research is required to better measure treatment effects, modification of MS natural history, and net societal costs of IFN beta-1b in RRMS.