Also, patients weighing more than 105 kg received a higher dose of ribavirin in the peginterferon alfa-2b arm (1,400 mg) compared with a lower dose of ribavirin (1,200 mg) in the peginterferon alpha 2a arm. Regardless, patients in the peginterferon alfa-2b arm achieved higher SVR compared with patients in the peginterferon alpha-2a arm (42%

versus 39%). It is also interesting that in the same trial, patients who developed anemia and thus required ribavirin dose reduction achieved a higher SVR than patients who did not require the ribavirin dose to be reduced. Accordingly, we do not think Depsipeptide nmr that the varying doses of ribavirin have major confounding influence on our observations regarding type of peginterferon. More research needs to be performed to explore the optimal ribavirin dose. Ribavirin dose reduction

due to adverse events was only reported in five trials.3, NVP-BEZ235 25, 26, 29, 30 Four of these trials applied the same dose reduction in both arms.25, 26, 29, 30 Only one trial applied different ribavirin dose reduction for two arms.3 Excluding this trial from our meta-analysis for SVR did not change our estimate. The strengths of this Cochrane Hepato-Biliary Group systematic review are that it is built on a peer-reviewed published protocol, used extensive searches until recently, considers risks of systematic errors (bias), and considers risks of random errors (chance) by adjusting the threshold for statistical significance according

to the information and strength of evidence in the cumulative meta-analysis. A possible limitation acetylcholine is the unavailability of full reports of all included trials. Two of the eight included trials in the meta-analysis for SVR are only available as abstracts. However, we were able to successfully retrieve the necessary data for one of the two abstracts via e-mail correspondence with the authors,28 and thus, the bias risk assessment of the included trial was performed to a satisfactory extent. Our sensitivity analysis did not show any important changes. In our study, the trials that were published as a full paper are large, and dominated the pooled estimates of effects. Moreover, empirical evidence suggests that trials that fail to refute the null hypothesis have lower odds of being published, especially those not funded by the industry.34–40 Thus, many of the included abstracts may have a low probability of being published. In fact, including these abstracts in our systematic review may likely be a strength rather than a limitation. By including abstracts, we are looking at the complete available body of evidence. By excluding abstracts, we would only be looking at a subset defined through the biased publication mechanisms of the present day, which would increase the likelihood of publication bias considerably. Selective outcome reporting was difficult to assess in this review.