Meta-analyses on viral hepatitis

This article summarizes the meta-analyses of interventions for viral hepatitis A, B, and C. Some of the interventions assessed are described in small trials with unclear bias control. Other interventions are supported by large, high-quality trials. Although attempts have been made to adjust for unclear bias control, analysis of publication bias and other biases is difficult when only few trials are available. It is possible that some of the meta-analyses presented in this article are biased. Furthermore, performing updated cumulative meta-analyses also may introduce random error.3,4 The extent and direction of bias may vary. On average, however, bias leads to overestimated intervention benefits.1 Accordingly, the benefit of some of the interventions suggested in this article may be exaggerated by systematic and random errors. Additional research including large, randomized trials is necessary to clarify the true intervention effects.