For the purposes of the calculation in this report, the committee assumed that there were four scenarios associated with MS. It was estimated that 15% of people with MS experience a lifelong, mild, intermittent disease, associated with an average health utility index (HUI) of .97. It was assumed that most (65%) cases of MS are associated with a relapsing, remitting MS that is associated with an average HUI of .61. 15% of patients were assumed to experience a chronic, progressive disease for 20 years until death from the disease. This is associated with an HUI of .47. The rapid, fulminant expression of MS was assumed to occur in 5% of patients and be associated with a 5-year period of an HUI of .31 until the time of death from the disease.

Table A15–1 summarizes the health care costs incurred by MS. For the purposes of the calculations in this report, it was assumed that for all scenarios there is a diagnostic phase, followed by a treatment phase which lasts the duration of the patients lifetime. The diagnostic phase was estimated to be approximately the same for all patients with MS: hospitalization and associated inpatient physician costs, visits to a specialist, and extensive diagnostics. For the purposes of the calculations in this report, it was assumed that no costs associated with the diagnostic phase of MS would be averted with a therapeutic vaccine strategy and are not described here. Chronic, treatment costs would be averted by a vaccine strategy.

The costs and patterns of care incurred during treatment phase vary greatly depending on the type of MS experienced. For example, it was assumed that all patients with benign and with relapsing-remitting MS visit a specialist and receive a diagnostic work-up each year for the duration of their lifetime. It was assumed that on average, 25% of patients with relapsing-remitting MS but none of the patients with benign MS require hospitalization each year. Patients with primary progressive MS were assumed to incur annual costs over 20 years associated with diagnostics, multiple specialist visits, hospitalization (50% of patients per year), and nursing home care (25% of patients). Patients with fulminant MS were assumed to incur annual costs for 5 years associated with diagnostics, specialist visits, hospitalization (25% of patients per year) and nursing home care (for 75% of patients).

The committee assumed that it will take 15 years until licensure of a therapeutic MS vaccine and that $360 million needs to be invested. Table 4–1