Thirteen studies were included (n=539): three randomised controlled trials (RCTs, n=85) and 10 non-randomised controlled trials (n=454). One RCT was double-blind.
Antiviral therapy was associated with a statistically significantly increased rate of achieving a sustained virological response (OR of failing to achieve sustained virological response using random-effects model was 0.081, 95% CI 0.029 to 0.230, p=0.0001). Significant heterogeneity was found (p=0.007, I2=59.7%). The test for funnel plot asymmetry was p=0.09. The number of null or negative trials required to make meta-analysis results non significant was 121.
Drop-out rates for patients on antiviral therapy ranged from 0% to 59%; in seven studies more than 20% dropped out. Antiviral therapy was associated with a statistically significant increase in drop-out rates (OR using random-effects model for control versus treatment was 0.389, 95% CI 0.155 to 0.957, p=0.04; 12 trials). Significant heterogeneity was found (p=0.004, I2=66.7%). The test for funnel plot asymmetry was p=0.001. The number of null or negative trials required to make meta-analysis results non significant was two.
Antiviral therapy was associated with a statistically significant increase in sustained virological response and no difference in drop-out rates for the four subgroups of studies: studies that evaluated conventional interferon monotherapy (nioe studies); RCTs in patients with chronic hepatitis C viral infection (three studies); studies that evaluated interferon monotherapy in dialysis patients with chronic hepatitis C viral infection (six studies); and studies that evaluated conventional interferon monotherapy in dialysis patients with chronic hepatitis C viral infection (five studies). No significant heterogeneity was found for any of these subgroup analyses.