The effects of interferon therapy in chronic hepatitis C patients on survival are unclear. However, a Japanese study has now attempted to cast some light on this subject.
Researchers from several universities and medical schools in Japan analyzed survival rates among 2889 chronic hepatitis C patients using a retrospective cohort study.
All subjects in the study had histologically proven hepatitis C, with 2430 patients receiving interferon therapy, and 459 patients remaining untreated.
For intervention, the median dose and duration of interferon administration were 480 million units and 137 days, respectively.
| Interferon therapy - cuts liver-related deaths in hepatitis C patients.
Medical records or direct questionnaires were used to confirm survival status.
The effect of interferon therapy on survival was assessed by standardized mortality ratio (SMR) based on published mortality among the Japanese general population and by risk ratio, calculated by proportional hazards regression.
A total of 30 of 459 untreated patients, 7 of 817 virologic sustained responders, and 49 of 1613 non-responders died in 5.4-years follow-up.
Of these 86 deaths, 58 (67%) were due to liver diseases (39 to hepatocellular carcinoma).
Compared with the general population, overall mortality was high among untreated patients (SMR: 1.9; CI: 1.3-2.8) but not among interferon-treated patients (SMR: 0.9; CI: 0.7-1.1).
More specifically, in the case of liver related death, the likelihood of dying was reduced, both among interferon-treated patients and sustained responders, when compared to the untreated group.
The researchers therefore conclude that interferon therapy improved survival of hepatitis C patients by preventing liver-related deaths.