Context Hepatitis C is the leading cause of chronic liver disease in the United
States. Several trials have found that interferon and ribavirin combination
therapy is more efficacious than interferon monotherapy for previously untreated
patients and those who relapsed after prior interferon monotherapy, but its
effectiveness for nonresponders to prior interferon monotherapy is unclear.
Objective To assess the efficacy and safety of interferon and ribavirin vs interferon
alone for treatment of patients with chronic hepatitis C who previously did
not respond to interferon monotherapy.
Data Sources A systematic search was performed using MEDLINE and the Science Citation
Index for publications from 1966 to December 1999. A manual reference search
and a manual review of relevant specialty journals also were performed, and
input from clinical hepatology experts was sought.
Study Selection Included studies were randomized, controlled clinical trials comparing
interferon and ribavirin with interferon alone and reporting virological and
biochemical outcomes after a follow-up period. Of 50 identified studies, 12
trials (941 patients) were included in the analysis.
Data Extraction Two investigators reviewed trials independently for methods, inclusion
and exclusion criteria, and outcomes. Disagreements were resolved by discussion.
Abstracted data included study and patient characteristics and virological,
biochemical, and histological outcomes. A quality evaluation questionnaire
was used to score studies.
Data Synthesis The pooled virological response rate for combination therapy was 14%
(95% confidence interval [CI], 11%-17%), with a risk difference favoring combination
therapy of 7% (95% CI, 2%-13%). Use of interferon alfa-2a/2b and ribavirin,
1000 to 1200 mg/d, was associated with a pooled virological response rate
of 18% and a risk difference of 16% (95% CI, 11%-21%). When interferon alfa-n/n3
and a lower dosage of ribavirin (600-800 mg/d) were used, the risk difference
was 0% (95% CI, –7% to 7%). Combination therapy was associated with
more adverse effects and an increased rate of discontinuation of treatment
compared with interferon monotherapy.
Conclusions For chronic hepatitis C that is nonresponsive to prior interferon monotherapy,
combination therapy is more effective than re-treatment with interferon alone.
Response rates remain less than 20% even in the most responsive subgroups,
demonstrating a need for better therapeutic options.