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Risk of bias (RoB) assessment is essential to the systematic review methodology. The new version of the Cochrane RoB tool for randomized trials (RoB 2) was published in 2019 to address limitations identified since the first version of the tool was published in 2008 and to increase the reliability of assessments. This study analyzed the frequency of usage of the RoB 2 and the adequacy of reporting the RoB 2 assessments in non-Cochrane reviews published in 2020. This meta-research study included non-Cochrane systematic reviews of interventions published in 2020. For the reviews that used the RoB 2 tool, we analyzed the reporting of the RoB 2 assessment. Among 3880 included reviews, the Cochrane RoB 1 tool was the most frequently used (N = 2228; 57.4%), followed by the Cochrane RoB 2 tool (N = 267; 6.9%). From 267 reviews that reported using the RoB 2 tool, 213 (79.8%) actually used it. In 26 (12.2%) reviews, erroneous statements were used to indicate the RoB 2 assessment. Only 20 (9.4%) reviews presented a complete RoB 2 assessment with a detailed table of answers to all signaling questions. The judgment of risk of bias by the RoB 2 tool was not justified by a comment in 158 (74.2%) reviews. Only in 33 (14.5%) of reviews the judgment in all domains was justified in the accompanying comment. In most reviews (81.7%), the RoB was inadequately assessed at the study level. In conclusion, the majority of non-Cochrane reviews published in 2020 still used the Cochrane RoB 1 tool. Many reviews used the RoB 2 tool inadequately. Further studies about the uptake and the use of the RoB 2 tool are needed. [ABSTRACT FROM AUTHOR]

The article discusses the increasing use of the Cochrane Risk of Bias 2 tool (RoB 2) in biomedical systematic reviews. A study of 3880 non-Cochrane systematic reviews published in 2020 found that the RoB 1 tool was used in 57.4% of reviews, while the RoB 2 tool was used in 6.9% of reviews. Another analysis of 1000 non-Cochrane systematic reviews published in 2023/2024 reported that 45% used the RoB 1 tool and 38% used the RoB 2 tool. The authors commend the availability of raw data for transparency and suggest further studies on the adequacy of RoB 2 tool usage in systematic reviews. [Extracted from the article]

Some Cochrane reviews were declared stable or closed, that is, not in need of updating. For some of them, it has been declared that conclusions will not (or it is unlikely they will) change with further studies. We explored whether there is a discernable decision‐making pattern for decisions about the conclusiveness and stabilization of these reviews. We analyzed Cochrane reviews published until April 2020 labeled as stable or closed. We extracted the rationale leading to the decision declaring that the conclusion is not expected to change with further studies. Furthermore, we assessed whether the reviews used GRADE analysis. We extracted data from summary of findings (SoF) tables on the direction of effect, statistical significance, and I2 values for the first and primary outcomes in SoFs, conclusions in the abstract and review, and implications for practice and future research. We included 40 stable/closed Cochrane reviews. Rationales for their stabilization did not enable any insight into the Cochrane's decision‐making algorithm for considering the evidence as conclusive. Among 191 outcomes presented in the SoFs, 70% were rated with either low or very low certainty evidence. None of the reviews mentioned in the text that the review should be stabilized or closed, or that there is sufficient evidence on the subject. Reasons for stabilizing/closing Cochrane reviews were unclear, and we could not discern any pattern of "conclusive review" traits. Definition of systematic review conclusiveness is still lacking, which may contribute to research waste. [ABSTRACT FROM AUTHOR]

Background: It is challenging to keep systematic reviews (SR) current and updated. Cochrane designated some of its SRs as "stable," that is, not in need of updating. The issue of stabilizing an SR is an important in research synthesis, because it could help reduce research waste. The aim of this study was to analyze publicly available justifications for stabilizing a Cochrane review, with the ultimate goal of helping to make decisions about whether the update of any SR is warranted. Methods: We analyzed Cochrane reviews labeled as stable in Archie, Cochrane's system for managing the editorial/publishing process. From the "What's new" section of the reviews in the Cochrane Library, we extracted justification for stabilization. Results: We included 545 Cochrane reviews labeled in Archie as stable on October 28, 2019. The most common of the five reasons for stabilization was that "last search did not identify any potentially relevant studies likely to change conclusions" (N = 99; 18%), followed by "research area no longer active" (N = 86; 16%), "review is or will be superseded" (N = 41; 7.5%), "evidence is conclusive" (N=35; 6.4%), and "intervention no longer in general use" (N = 34; 6.2%). For the 269 (49%) Cochrane reviews, we considered that the justification for stabilization was not clearly described, that is, sufficiently informative. Conclusions: Cochrane reviews would benefit from more transparency and consistency in publicly available justifications for stabilizing reviews. Further work in this field will help make decisions about the futility of further research and deciding on enough evidence in the field of research synthesis. [ABSTRACT FROM AUTHOR]