Economic burden of multiple sclerosis: what can we learn from cost-of-illness studies?

The purpose of this article is to provide a critical evaluation of the available literature describing the economic burden of multiple sclerosis and to assess the gaps in information. The studies included in this review describe costs in patients categorized into severity groups according to the Expanded Disability Status Scale levels. Despite the differences in methodology, as well as differences between countries in absolute and relative prices and organization of healthcare systems, all cost-of-illness studies demonstrate that multiple sclerosis represents a major financial burden on the individual, family, health services and society in all countries studied, and that a positive relationship exists between costs (both direct and indirect) and level of disability measured by Expanded Disability Status Scale level. The results of the cost-of-illness studies in the field of multiple sclerosis can be used as an input into future economic evaluation, but provide no useful information about future resource allocation on their own. The current focus of future research efforts should be in refining economic methods, specifically for indirect costs, improving interpretation and communication of study findings and conducting cost-effectiveness assessments of interventions based on results of cost-of-illness studies. Further research should be targeted to patients treated with new disease-modifying drugs.