Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
End of treatment virological response
RCT	4913 people with HCV (mixed genotype)	Proportion of people achieving end of treatment virological response 48 weeks 57% with peginterferon alfa-2b plus fixed-dose ribavirin 59% with peginterferon alfa-2b plus variable-dose ribavirin Absolute numbers not reported	P = 0.082		Not significant
RCT	2618 people with HCV genotype 1 Subgroup analysis	Proportion of people achieving end of treatment virological response 48 weeks 46% with peginterferon alfa-2b plus fixed-dose ribavirin 49% with peginterferon alfa-2b plus variable-dose ribavirin Absolute numbers not reported	P = 0.077		Not significant
Sustained virological response
RCT 3-armed trial	1530 previously untreated people with HCV	Proportion of people achieving SVR 274/511 (54%) with higher-dose peginterferon alfa-2b plus ribavirin 244/514 (48%) with lower-dose peginterferon alfa-2b plus ribavirin	P = 0.01 The RCT did not carry out an analysis of the effects of variation in ribavirin dose	Effect size not calculated	higher-dose peginterferon plus ribavirin
RCT 3-armed trial	697 people with HCV genotype 1 Subgroup analysis	Proportion of people achieving SVR 145/348 (42%) with higher-dose peginterferon alfa-2b plus ribavirin 118/349 (34%) with lower-dose peginterferon alfa-2b plus ribavirin	Significance not assessed The RCT did not carry out an analysis of the effects of variation in ribavirin dose The results of this RCT suggest that a high dose of peginterferon plus ribavirin may be more beneficial in people with HCV genotype 1
RCT 3-armed trial	300 people with HCV genotype 2 or 3 Subgroup analysis	Proportion of people achieving SVR 121/147 (82%) with higher-dose peginterferon alfa-2b plus ribavirin 122/153 (0%) with lower-dose peginterferon alfa-2b plus ribavirin	Significance not assessed The RCT did not carry out an analysis of the effects of variation in ribavirin dose
RCT	4913 people with HCV (mixed genotype)	Proportion of people achieving SVR 852/2102 (41%) with peginterferon alfa-2b plus fixed-dose ribavirin 938/2121 (44%) with peginterferon alfa-2b plus variable-dose ribavirin	P = 0.008	Effect size not calculated	variable-dose ribavirin plus peginterferon
RCT	4913 people with HCV (mixed genotype) Sensitivity analysis	Proportion of people achieving SVR 42% with peginterferon alfa-2b plus fixed-dose ribavirin 45% with peginterferon alfa-2b plus variable-dose ribavirin Absolute numbers not reported	P = 0.021	Effect size not calculated	variable-dose ribavirin plus peginterferon
RCT	2618 people with HCV genotype 1 Subgroup analysis	Proportion of people achieving SVR 377/1035 (29%) with peginterferon alfa-2b plus fixed-dose ribavirin 447/1313 (34%) with peginterferon alfa-2b plus variable-dose ribavirin	P = 0.005	Effect size not calculated	variable-dose ribavirin plus peginterferon