Multiple sclerosis (MS) is a common, neurological autoimmune disease that affects approximately 400 000 individuals in the US alone. Its effects on patients' central nervous systems can be debilitating, and often result in chronic morbidity and disability, which takes a substantial financial toll on society. Several studies presented at the 9th Annual Meeting of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) [Arlington, Virginia, US; May 2004] considered the economic burden of MS, and the cost effects associated with drug treatments.