Cost-effectiveness analysis of interferon beta-1b as treatment for patients with clinically isolated syndrome suggestive of multiple sclerosis in Spain

Abstract

IntroductionThe BENEFIT study has demonstrated the benefits of early treatment with interferon beta 1b (IFNβ-1b). The objective of this study was to estimate the efficiency of early vs. delayed IFNβ-1b treatment in patients with clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS) in Spain. MethodsA Markov model reflecting the social perspective was developed with time horizons ranging from 2 years to lifetime. A cohort of 1000 patients with CIS, whose health status had been measured on the Expanded Disability Symptom Scale (EDSS), included patients who received early IFNβ-1b treatment and those who did not. Data from the BENEFIT study were used to model EDSS progression and transitions to MS. Costs were estimated from published literature. Patient utilities were derived from EQ-5D data and published data. Mortality was estimated using life tables and EDSS data. Costs (€ at 2013 rates) and outcomes were discounted at 3% per annum. A probabilistic sensitivity analysis was performed. ResultsIn the base case, both the incremental cost utility ratio (ICUR) and the incremental cost effectiveness ratio (ICER) of IFNβ-1b vs. no treatment were dominant (more effective and less costly) from a social perspective. From the perspective of the Spanish Health System, the ICUR was € 40702/QALY and the ICER was € 13/relapse avoided. ConclusionEarly treatment with IFNβ-1b after a CIS vs. delayed treatment is efficient from a social perspective, but it may not be efficient from the perspective of the NHS which does not take non health-related costs into account.