For the purposes of the calculation in this report, the committee assumed that 30% of people with HCV infection experience only an acute and mild disease lasting approximately 2 weeks. The health utility index (HUI) associated with this illness is .9. It was assumed that 50% of people with HCV infection experience lifelong but very mild intermittent illness (HUI of .97). It was assumed that 7% of HCV infections lead to chronic hepatitis associated with a rapid, progressive course leading to death within 7 years of infection. The remaining 13% of HCV infections were associated with the mortality from cirrhosis and liver failure 25 years after infection and cirrhosis and liver cancer 30 years after infection. See Table A8–1.

Table A8–2 summarizes the health care costs incurred by HCV infections. For the purposes of the calculations in this report, it was assumed that a relatively small fraction of patients experiencing mild symptoms of acute hepatitis seek medical treatment. Hospitalization and related costs are included for a very few patients. For the 50% of patients with HCV who have lifelong, uncomplicated, mild hepatitis, it was assumed that, on average, 10% of these people see a physician for illness associated (but unrecognized in many cases) with the HCV infection.

HCV infections associated with a chronic course but leading to severe liver disease was associated with 20 and 30 years of treatment for low grade symptoms (diagnosed as HCV-related or not). 10% of patients visit a specialist every other year. The 4-year symptomatic phase was associated with quarterly specialist visits, 2 hospitalizations, and a biopsy (for 10% of the patients). The year spent in terminal cirrhosis, liver failure, or liver cancer was assumed to be associated with a hospitalization and monthly specialist visits.

The rapid, progressive course of HCV disease was assumed to be associated with antiviral medication, bimonthly specialist visits, 2 extensive diagnostics per year for 6 years, and 1 hospitalization during that time period. The final year of life was assumed to be associated with hospitalization and monthly visits to a specialist.

The committee assumed that it will take 15 years until licensure of an HCV vaccine and that $360 million needs to be invested. Table 4–1 summarizes vaccine development assumptions for all vaccines considered in this report.