Abstract
This article compares the findings of several evaluation studies undertaken to assess the economic cost and burden of multiple sclerosis (MS) therapies, and discusses issues for future research. Despite major design differences, all studies show that indirect costs are the dominating economic burden for MS, but none has addressed changes after intervention. Before beta interferon therapy, no available intervention had a potential effect on the natural course of MS. Therefore, the probability of cost offsets through substitution is low, and the cost of any treatment needs to show explicit benefits. The ideal outcome measure for MS is the quality-adjusted life year (QALY), which allows comparison of results across different diseases and influences decision-making about resource allocation. The potentially high cost of MS therapy makes it crucial to incorporate all benefits and costs into economic evaluations, using models that include probability and severity of relapse, as well as disease progression and all other costs. No analysis undertaken to date fulfils these criteria completely.