Error Matrix Tool to Overview the Validity of Evidence on Radix Sophorae flavescentis for Chronic Hepatitis B

To introduce a conceptualized visual error matrix tool to overview the validity of evidence by taking Radix Sophorae flavescentis for chronic hepatitis B as an example and to propose recommendations for improving clinical trial design and evidence quality. The randomized clinical trials and reviews were collected during the conduct of a Cochrane systematic review. The authors used a visual error matrix tool to overview the evidence validity by looking at systematic, random, and design error risks. Systematic errors were measured by the type of evidence. Random errors were expressed by the standard error (SE). Design errors were assessed on the priority of outcome measures and the adequacy of nine design components. Three-dimensional error matrix on benefits and harms were then constructed. The authors included 6 meta-analyses and 28 randomized clinical trials. In terms of systematic errors, all reviews were at critically low quality, and all included randomized trials were assessed at high risk of bias. On this systematic error level, they found that there was substantial risk of random errors regarding all-cause mortality (SE 0.36), moderate risk regarding serious adverse events (SE 0.22), substantial risk regarding nonserious adverse events (SE 0.35), and small to moderate risk regarding surrogate outcomes such as detectable hepatitis B e-antigen (HBeAg) and detectable hepatitis B virus (HBV)-DNA (SE 0.16 and 0.21). No study reported results on quality of life, hepatitis B-related mortality, and morbidity. The design error risks were mainly misuse of outcomes (14/34), inadequate selection of participants (5/34), inadequate description of intervention (11/34) and control (9/34), single-center setting (33/34), and unclear study objective regarding superiority, equivalence, or noninferiority. The current evidence on Radix S. flavescentis for chronic hepatitis B showed high risks of systematic errors, moderate or high risks of random errors, and high risks of design errors. These findings suggest that more randomized trials at minimum risks of all three errors are needed to assess the benefits and harms of Radix S. flavescentis for chronic hepatitis B. The visual error matrix tool provides an overview of the reliability of evidence and may assist in design and conduct of future randomized trials.