Evaluation of outcomes reported in randomized controlled trials for herbal remedies for adults with chronic hepatitis C

Background: Herbal remedies have been widely utilized in treating chronic hepatitis C (CHC) worldwide. Selecting appropriate outcomes to reflect both beneficial and harmful effects is a crucial step in designing randomized controlled trials (RCTs). This study evaluated the outcomes reported in RCTs on herbal remedies for CHC with comparison to the core outcomes recommended by the Cochrane Hepato-Biliary Group (CHBG), to check the consistency of the outcomes and to provide recommendation for future researches. Methods: A systematic literature search was conducted in Western and Chinese databases to identify RCTs on herbal remedies for adults with CHC. For each trial, all the outcomes reported in the results section were collected. Comparison between trial outcomes and CHBG core outcomes were evaluated and summarized with descriptive statistics. Results: A total of 116 RCTs involving 9154 participants were included; 27 outcomes were identified. Commonly reported outcomes included alanine aminotransferase (64 trials, 55.2%), adverse events (58 trials, 50.0%), and end-of-treatment virological response (50 trials, 43.1%). All trials indicated that the herbal remedies under investigation had a positive effect and was markedly more effective than the control. Nearly half of the trials reported that the combination of herbal medicine and antiviral drugs could ameliorate adverse events. Very few trials reported primary core outcomes relating survival and quality of life. The most frequently reported core outcomes are non-serious adverse events (54 trials, 46.6%), viral response (27 trials, 23.3%), and biochemical response (24 trials, 20.7%). Conclusion: The variation and inconsistency in trial outcomes impedes research synthesis efforts, and indicate the need for comparable outcomes through the development of core outcome sets in CHC. The low concordance of outcome reporting could be improved by following CHBG core outcomes recommendation. Keywords: Chronic hepatitis C, Herbal, Core outcome set, Randomized controlled trial, Cochrane Hepato-Biliary Group