Estimating progression to cirrhosis in chronic hepatitis C virus infection

To gain a clearer understanding of the rate of progression to cirrhosis and its determinants in chronic hepatitis C virus (HCV) infection, a systemati c review of published epidemiologic studies that incorporated assessment fo r cirrhosis has been undertaken. Inclusion criteria were more than 20 cases of chronic HCV infection, and information on either age of subjects or dur ation of infection. Of 145 studies examined, 57 fulfilled the inclusion cri teria. Least-squares linear regression was employed to estimate rates of pr ogression to cirrhosis, and to examine for factors associated with more rap id disease progression in 4 broad study categories: 1) liver clinic series (number of studies = 33); 2) posttransfusion cohorts (n = 5); 3) blood dono r series (n = 10); and 4) community-based cohorts (n = 9). Estimates of pro gression to cirrhosis after 20 years of chronic HCV infection were 22% (95% CI, 18%-26%) for liver clinic series, 24% (11%-37%) for posttransfusion co horts, 4% (1%-7%) for blood donor series, and 7% (4%-10%) for community-bas ed cohorts. Factors that were associated with more rapid disease progressio n included older age at HCV infection, male gender, and heavy alcohol intak e. Even after accounting for these factors, progression estimates were much higher for cross-sectional liver clinic series. Selection biases probably explain the higher estimates of disease progression in this group of studie s. Community-based cohort studies are likely to provide a more representati ve basis for estimating disease progression at a population level. These su ggest that for persons who acquire HCV infection in young adulthood, less t han 10% are estimated to develop cirrhosis within 20 years.