Natural history models for hepatitis C-related liver disease: different disease progression parameters for different settings

An understanding of the natural history of hepatitis C virus (HCV) infection has improved in recent years. Estimates of liver disease progression among people with chronic hepatitis C have been developed from various study populations, including liver clinics, post-transfusion hepatitis C cohorts and community-based cohorts. These estimates can be used in hepatitis C natural history models; however, they need to be matched to differing requirements. Estimation and projection of liver disease burden at the population level requires estimates of HCV prevalence and incidence, and disease progression among all people with chronic hepatitis C. Liver disease progression based on community cohorts would appear the most appropriate for a population level model. In contrast, models that examine the cost-effectiveness of antiviral therapy for people with chronic hepatitis C require disease progression estimates from the treatment setting. Further models are required to determine individual prognosis and should be based on an assessment of cofactors for liver disease progression.