Background aims: In hepatitis C there is controversy over the linearity of the rate of progression and the significance of gender, mode of infection and viral factors.
Methods: 2313 untreated patients with a reliable estimated duration of infection and liver fibrosis were included. Fibrosis progression was calculated using the Kaplan-Meier method and the rate of fibrosis progression using the hazard function. Seven risk factors were assessed: age at biopsy, gender, alcohol consumption, mode of infection, activity grade, hepatitis C virus genotype and RNA level.
Results: The percentage of patients without cirrhosis was 91% after 20 years of infection (95% CI:90-92%) and 56% after 40 years (95% CI:48-64%). Three independent factors were associated (P < 0.001) with a faster progression rate: age at infection, alcohol consumption of 50 g or more per day, and male gender. The mode of infection, histologic activity, genotype and viral load were not independently associated with fibrosis. Fibrosis progression was mainly dependent on age and the duration of infection and can be divided into four successive periods with very slow, slow, intermediate and rapid progression rates.
Conclusion: In patients infected with hepatitis C, the majority of fibrosis progression occurred in those aged fifty years or older.