Most Cochrane systematic reviews and protocols did not adhere to Cochrane’s Risk of Bias 2.0 tool

Objective: To identify the frequency of Cochrane systematic reviews (CSR) and CSR protocols using (or planning to use) the RoB 2.0 to assess the risk of bias of the included randomized clinical trials (RCTs).Study design: meta-research study.Methods: We included CSR or CSR protocol that planned to include RCTs. We assessed the Cochrane Database of Systematic Reviews and screened for issues published after the launch of RoB 2.0 (2019 to 2022). Two independent investigators performed the study selection and data extraction. Results: We analyzed 440 CSR and 536 CSR protocols. Overall, 4.8% of the CSR and 28.5% of the CSR protocols used or planned to use the RoB 2.0. Although low, adherence is increasing over time. In 2019, 0% CSR used RoB 2.0 compared to 24.1% in 2022. In CSR protocols, adherence increased from 6.9% in 2019 to 41.5% in 2022. A total of 274 CSRs (62.1%) had their protocols published before 2018; only one used RoB 2.0 and reported the change of versions in the Differences between protocol and revision section.Conclusion: Cochrane’s RoB 2.0 tool has low adherence among Cochrane protocols and systematic reviews. Further efforts are necessary to facilitate the implementation of this new tool.