Effects of adding ribavirin to interferon to treat chronic hepatitis C infection: a systematic review and meta-analysis of randomized trials.

Evidence shows that a combination therapy of ribavirin plus interferon clears hepatitis C virus from the blood in about 40% of patients with chronic hepatitis C infection, but the effects on clinical outcomes are unclear. We evaluated the beneficial and harmful effects of ribavirin plus interferon vs interferon alone for treatment of patients with chronic hepatitis C infection. Randomized trials were included irrespective of blinding, language, or publication status. Trials were identified through the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Library, MEDLINE, EMBASE, manual searches of bibliographies and journals, and correspondence with experts (in May 2004). Data were extracted independently by 2 reviewers. The primary outcomes were morbidity plus mortality and viral clearance. Secondary outcomes included histologic response, quality of life, and adverse events. Previous antiviral therapy (treatment-naive patients, relapsers, or nonresponders), patient characteristics, treatment regimen, methodological quality, and duration of follow-up were extracted. We included 72 trials with a total of 9991 enrolled patients. Treatment with ribavirin plus interferon significantly reduced morbidity plus mortality (Peto odds ratio, 0.46; 95% confidence interval [CI], 0.22-0.96) and significantly improved sustained viral clearance in treatment-naive patients (risk ratio, 0.72; 95% CI, 0.68-0.76), relapsers (risk ratio, 0.63; 95% CI, 0.54-0.73), and nonresponders (risk ratio, 0.89; 95% CI, 0.84-0.94). Combination therapy also significantly improved liver histologic response. The effects on quality of life are unclear. However, combination therapy significantly increased the risk of hematological, dermatological, gastrointestinal, and several other types of adverse events. In conclusion, the effect of ribavirin plus interferon on viral clearance may lead to reduced mortality and morbidity in patients with chronic hepatitis C infection. However, combination therapy is associated with increased risk for adverse events.