RoB 2
RoB 2 is a tool used to assess how reliable the results of a randomized trial are by checking for potential biases. It helps reviewers judge whether a study's design and reporting might have distorted its findings.
At a glance
Use when
Conducting a systematic review of randomized trials where assessing the reliability of evidence is critical.
Avoid when
Assessing non-randomized studies or when insufficient trial details are available to make informed judgments.
Inputs
Full reports of randomized trials, including protocols, publications, and supplementary materials.
Outputs
Structured risk-of-bias judgments per domain and an overall risk-of-bias assessment for each outcome in a trial.
How it works
RoB 2 is a revised, domain-based tool for assessing risk of bias in randomized controlled trials. It evaluates bias across five domains: randomization process, deviations from intended interventions, missing outcome data, outcome measurement, and selection of reported result. Each domain is assessed for risk of bias, leading to an overall judgment. The tool supports structured, transparent, and consistent appraisal within systematic reviews.
- HTA domains
- Clinical Effectiveness
- Categories
- Appraisal
- Assumptions
- Bias can be systematically identified through predefined domains; transparency in reporting allows for accurate judgment; domain-level assessments can be synthesized into an overall judgment.
- Strengths
- Updated based on empirical evidence and user feedback,Domain-based structure improves precision and transparency,Guidance and signaling questions support consistent application,Designed for use in systematic reviews and meta-analyses
- Limitations
- Requires detailed trial reporting for accurate assessment,Subjectivity remains despite structured guidance,Time-intensive to apply thoroughly,Limited applicability to non-randomized study designs
- Also known as
- Cochrane Risk of Bias Tool 2, RoB 2.0, Revised Cochrane Risk of Bias Tool
Questions this answers
- › Was the randomization process adequately conducted to prevent bias?
- › Were there deviations from the intended interventions that could introduce bias?
- › Could missing outcome data have affected the results?
- › Was the outcome measured in a way that minimizes bias?
- › Is the reported result likely to be selected from multiple analyses (reporting bias)?
- › What is the overall risk of bias in the trial's result?
References & sources
Beta record. Generated from the primary source via AI extraction and independent audit, pending final human review.