Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Sustained virological response
Systematic review	1208 people 12 RCTs in this analysis	Proportion of people failing to achieve sustained virological response (SVR) 328/639 (51%) with interferon alfa plus ribavirin 497/569 (87%) with interferon alfa monotherapy	RR (for failing to achieve SVR) 0.60 95% CI 0.55 to 0.65	Small effect size	interferon alfa plus ribavirin