The Risk of Bias 2 tool is Underutilised in Cochrane Intervention Reviews: Findings from a Cross-Sectional Survey

Session Type
Lv M1, Luo X2
1School of Public Health, Lanzhou University, China
2Evidence-Based Medicine Center, School of Basic Medical Sciences, Lanzhou University, China

Background: Since August 2019, Version 2 of the Cochrane risk-of-bias tool for randomised trials (RoB 2) has been the recommended tool for assessing the risk of bias in randomised trials included in Cochrane Reviews. However, what proportions of Cochrane Intervention Reviews choose to use the tool remains unclear.
Objectives: To assess whether the RoB 2 tool has been fully used in Cochrane Intervention Reviews since 2020.
Methods: We conducted a search of Cochrane Intervention Reviews published in the Cochrane Library between January 1, 2020, and January 1, 2023, to identify studies that applied RoB 2 to evaluate the risk of bias in randomised controlled trials. We also extracted basic information about these studies including the publication date and the corresponding author’s country.
Results: During the period from January 1, 2020, to January 1, 2023, a total of 1275 Cochrane Intervention Reviews were published in the Cochrane Library, but only 78 of them (6.1%) used RoB 2 tool for assessing the risk of bias in randomised controlled trials. Among these 78 reviews, 6 (7.7%) were published in 2020, 28 (35.9%) in 2021, and 44 (56.4%) in 2022. In terms of the corresponding author’s country, the most were from Germany (20 reviews, 25.6%), followed by the United Kingdom (16 reviews, 20.5%) and Australia (7 reviews, 9.0%).
Conclusions: The number of Cochrane Intervention Reviews using the RoB 2 tool has risen steadily since its published. However, the tool has still not been generally used by Cochrane review authors. Compared with the original RoB tool, RoB 2 has improved and addressed many limitations. Thus there is a great need to promote the utilisation of the RoB 2 tool and to make the research findings more reliable.
Patient, public and/or healthcare consumer involvement: None