Adherence of Cochrane reviews and protocols to the Cochrane's risk of bias 2.0 tool
Rachel Riera, Hospital Sírio-Libanês / Universidade Federal de São Paulo / Cochrane Affiliate Rio de Janeiro
2Universidade Metropolitana de Santos – Santos (SP, Brazil
3Universidade Metropolitana de Santos – Santos (SP), Brazil
4Universidade Metropolitana de Santos, Postgraduate Program of Health and Environment – Santos (SP), Brazil
5Universidade Federal de São Paulo – São Paulo (SP). Hospital Sírio-Libanês, Centre of Health Technology Assessment – São Paulo (SP). Centro Universitário São Camilo – São Paulo (SP), Brazil
6Universidade Federal de São Paulo – São Paulo (SP). Hospital Sírio-Libanês, Centre of Health Technology Assessment – São Paulo (SP), Brazil
Background: Assessing the risk of bias in individual studies is an important step when conducting a systematic review and key criteria for assessing the certainty of the body of evidence. Neglecting potential biases can directly impact the estimated effects of the intervention, lead to uncertain conclusions and undermine the basis for decision-making in clinical practice. In this setting, despite the improvement in the interpretation of bias and its influence on the randomized clinical trials results, Cochrane's risk of bias 2.0 tool (RoB 2.0) has a more complex structure than its original version, and there is a growing discussion around its applicability and usability, which seems to limit its wide adoption.
Objectives: To identify the frequency of Cochrane systematic reviews and protocols using (or planning to use) the RoB 2.0.
Methods: A cross-sectional analysis  conducted at Universidade Metropolitana de Santos (Unimes), Santos, São Paulo, Brazil, in collaboration with the Evidence-Based Medicine Discipline, Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp), Brazil.
Results: 440 Cochrane systematic reviews and 53 protocols were analysed. Overall, 4.8% of the reviews and 28.5% of the protocols used or planned to use the RoB 2.0 tool. Although currently low, adherence is increasing over time. In 2019, None Cochrane review used RoB 2.0 tool, compared to 24.1% in 2022. For Cochrane protocols, adherence increased from 6.9% in 2019 to 41.5% in 2022. A total of 274 (62.1%) Cochrane reviews had their protocols published before 2018; only one used RoB 2.0 tool and reported the change of versions in the “Differences between protocol and revision” section.
Conclusions: The Cochrane RoB 2.0 tool has low adherence among Cochrane protocols and systematic reviews. Additional efforts are needed to enhance the implementation of this tool.
Patient, public and/or healthcare consumer involvement: The lack of standardization and competencies to use RoB 2.0 may lead to flawed and/or unreliable conclusions from reviews, reducing its applicability and trustworthiness as a basis for decision-making. Reference 1. Martimbianco ALC, et al. Most Cochrane systematic reviews and protocols did not adhere to the Cochrane's risk of bias 2.0 tool. Rev Assoc Med Bras [Internet]. 2023.