Contribution of intangible costs to the economic burden of multiple sclerosis

Multiple sclerosis (MS) is associated with a substantial economic burden resulting from direct medical costs associated with health and disability-related resource utilization and indirect costs relating to reduced productivity. However, reduced health-related quality of life (HR-QOL) may be associated with additional costs, often termed 'intangible costs,' that should be considered as part of the economic burden from the societal or patient perspectives.

To review the contribution of intangible costs to the overall economic burden of MS.

Medline was searched through March 2010 for relevant articles that included the terms 'multiple sclerosis' in combination with 'intangible costs,' 'QALY,' 'quality-adjusted life year,' 'willingness-to-pay,' and 'WTP.' Other than the restriction that the articles were published in English, there were no other exclusionary criteria for the search. Identified references were hand-searched to determine if intangible costs were estimated.

Thirteen studies across ten countries were identified that estimated intangible costs based on the number of quality-adjusted life-years (QALYs) lost due to a reduction in HR-QOL multiplied by accepted willingness-to-pay (WTP) thresholds. Although absolute costs varied depending on thresholds used and year of evaluation, the intangible costs accounted for 17.5-47.8% of total costs of MS. Furthermore, evidence suggested intangible costs are positively correlated with worsening disability. The largest increase in intangible costs occurred at the transition between mild and moderate disability. However, since no value has been established as being acceptable to pay for a QALY, a limitation of these studies was their dependence on the definition of the WTP threshold.

Intangible costs substantially add to the economic burden of MS. There is not only a need to further characterize these costs and incorporate them into economic studies, but also to determine how these costs can be reduced through appropriate management strategies.