Factors associated with severity of hepatic fibrosis in people with chronic hepatitis C infection

Objective: To determine factors associated with hepatic fibrosis development in people with chronic hepatitis C virus (HCV) infection. Methods: As a requirement for access to interferon therapy through the S100 scheme in Australia, individual pretreatment demographic and clinical information was collected on 2986 patients from 61 hospital-based liver clinics from 1 October 1994 through 31 December 1996. Patients with both a hepatic fibrosis score and an estimated duration of HCV infection (910) were divided into 540 with no or minimal hepatic fibrosis (stage 0-1) and 370 with moderate to severe hepatic fibrosis (stage 2-3). Seven factors were examined: age at HCV infection, sex, ethnicity, source of infection, duration of infection, alcohol intake, and mean ALT level. A further analysis was performed for all 1135 patients with a hepatic fibrosis score disregarding age at and duration of HCV infection. Results: In multivariate analysis, four factors were significantly associated with moderate to severe hepatic fibrosis: age at infection (OR, 2.33 for age 31-40 years, 5.27 for age > 40 years, and 0.20 for age < 15 years, compared with 15-20 years); duration of infection (OR, 1.44 for 11-20 years, 2.74 for 21-30 years, and 8.71 for > 30 years, compared with < 11 years); alcohol intake in previous six months (OR, 1.51 for any intake, compared with none); and mean ALT level (OR, 1.81 for 2-3 times, 2.27 for > 3 times, compared with 1.5-2 times the upper limit of normal). In the analysis disregarding age at HCV infection and duration of HCV infection, older age was strongly associated with moderate to severe hepatic fibrosis (OR, 2.32 for age 36-40 years, 2.46 for age 41-50 years, 7,87 for age 51-60 years, and 7.15 for age > 60 years, compared with 16-30 years). There was no association in either analysis with sex or source of HCV infection. Conclusion: These factors may assist in targeting patients for both liver biopsy-based investigation and therapeutic intervention.