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Cochrane RoB 2 calculator

Work through the signalling questions for a randomized trial and see the algorithm’s suggested domain and overall judgments. Your answers stay in this browser.

Randomized trials · Select an answer for each signalling question. The suggested judgments update as you go.

Domain 1: Bias arising from the randomization process

1.1 Was the allocation sequence random?1.2 Was the allocation sequence concealed until participants were enrolled and assigned?1.3 Did baseline differences suggest a problem with randomization?

Suggested judgment: Complete required questions to calculate

Domain 2: Bias due to deviations from intended interventions

2.1 Were participants aware of their assigned intervention?2.2 Were carers or intervention deliverers aware of assignments?2.3 Were there deviations from intended intervention because of the trial context?2.4 Were these deviations likely to affect the outcome?2.5 Were deviations balanced between groups?2.6 Was an appropriate analysis used to estimate the effect of assignment?2.7 Could failure to analyse participants as randomized substantially affect the result?

Suggested judgment: Complete required questions to calculate

Domain 3: Bias due to missing outcome data

3.1 Were outcome data available for all or nearly all randomized participants?3.2 Is there evidence the result was not biased by missing outcome data?3.3 Could missingness depend on the true value of the outcome?3.4 Is it likely missingness depended on the true outcome value?

Suggested judgment: Complete required questions to calculate

Domain 4: Bias in measurement of the outcome

4.1 Was the method of measuring the outcome inappropriate?4.2 Could outcome measurement have differed between groups?4.3 Were outcome assessors aware of the intervention received?4.4 Could assessment have been influenced by knowledge of intervention?4.5 Is it likely assessment was influenced by that knowledge?

Suggested judgment: Complete required questions to calculate

Domain 5: Bias in selection of the reported result

5.1 Was the analysis in line with a pre-specified plan finalized before unblinded data were available?5.2 Could this result have been selected from multiple eligible outcome measurements?5.3 Could this result have been selected from multiple eligible analyses?

Suggested judgment: Complete required questions to calculate

Overall suggested risk: Complete all five domains

About this RoB 2 calculator

This tool implements the EvidenceFlow RoB 2 signalling-question algorithms for randomized trials. It provides suggested judgments from the answers entered; reviewers should consider the study context and document the rationale for each judgment.

The full RoB 2 tool has variants for cluster-randomized and crossover trials, and domain 2 targets a specific estimand. This page is a local aid for the standard individually randomized parallel-group trial, not an official Cochrane product.

FAQ

Frequently asked questions

What does NI mean?+

NI means no information. Select it when the available report does not allow you to answer yes or no with confidence.

Can I save my answers?+

This standalone calculator does not save answers. Your entries remain in the current browser page. The EvidenceFlow review workspace supports saved assessments.

Is this an official Cochrane tool?+

No. It is an independent aid implementing the RoB 2 signaling-question algorithms. Consult the official RoB 2 guidance and use reviewer judgment.

For saved study-level assessments alongside screening and extraction, start a free EvidenceFlow review.

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