Seventeen RCTs comparing interferon with control in chronic hepatitis C (831 patients); 10 RCTs comparing different doses of interferon in chronic hepatitis C; 6 RCTs comparing different duration of treatment with interferon in chronic hepatitis C; and 4 RCTs comparing interferon with control in acute hepatitis C (134 patients).
Chronic hepatitis: the standard regimen was associated with an increase of the complete ALT response rate by 45% (95% confidence interval, CI: 35, 55, p<0.001); intervention and control group response rates were 47 and 2%, respectively. The standard regimen was associated with an increase of the sustained ALT response rate by 21% (95% CI: 13, 28, p<0.001); intervention and control group sustained response rates were 22 and 1% respectively. For the 2 RCTs using the standard regimen, which reported histological outcome data, 67% (33 out of 49 patients) in the intervention groups and 15% (7 out of 45 patients) in the control groups showed improvement. An increased dose of 6 MU for the same 6-month period was associated with non statistically-significant increases in both complete and sustained ALT response rates, compared with the standard regimen. A 6 MU dose for 12 months produced a higher rate of complete and sustained responses when compared with a 3 MU dose for 12 months, and these differences were statistically significant. Complete response rates: 6 MU for 6 months, 62%; 3 MU for 12 months, 54%; 6 MU for 12 months, 69%. Sustained response rates: 6 MU for 6 months, 28%; 3MU for 12 months, 28%; 6 MU for 12 months, 46%.
Acute hepatitis C: Complete response rates were 69% in the interferon group (3 MU, three times per week for 3 months) and 29% in the control group. The mean difference was 40% (95% CI: 25, 55, p<0.001). Sustained response rates were 53% in the interferon group and 32% in the control group. The mean difference was 21% (95% CI: 3, 39, p=0.02).
Reported side-effects included flu-like syndromes (reported in 41% of patients treated with a standard regime), alopecia (16%) and depression (7%).