RoB 2 tool

A revised Cochrane risk of bias tool for randomized trials

A revised tool to assess risk of bias in randomized trials (RoB 2)

Welcome to the website for the RoB 2 tool.

The latest version (October 2018) is suitable for individually-randomized, parallel-group trials.

We are also maintaining an archive of the previous version, which had variants for three different trial designs (see below).

Citing the tool

As an interim measure, the revised tool may be cited as: Higgins JPT, Sterne JAC, Savović J, Page MJ, Hróbjartsson A, Boutron I, Reeves B, Eldridge S. A revised tool for assessing risk of bias in randomized trials In: Chandler J, McKenzie J, Boutron I, Welch V (editors). Cochrane Methods. Cochrane Database of Systematic Reviews 2016, Issue 10 (Suppl 1). dx.doi.org/10.1002/14651858.CD201601.

This work was supported by the MRC Network of Hubs for Trials Methodology Research (MR/L004933/1- N61). Infrastructure support was provided by the Medical Research Council ConDuCT-II Hub (Collaboration and innovation for Difficult and Complex randomized controlled Trials In Invasive procedures – MR/K025643/1).

A new version of the risk of bias tool is available from 12 September 2018.

Available:

  • Background information and detailed guidance for using the RoB 2.0 tool.
  • The tool itself
  • Blank template for completing the tool
    • Implement RoB 2.0 when interest is in the effect of assignment to intervention
    • Implement RoB 2.0 when interest is in the effect of starting and adhering to intervention
  • Excel implementation of the tool (cross-over trials) (contains macros)

View videos: RoB 2.0 tool Part 1, RoB 2.0 tool Part 2, RoB 2.0 tool Part 3, RoB 2.0 tool Part 4.

Available:

  • Background information and detailed guidance for using the RoB 2.0 tool for cluster-randomized trials
  • The tool (cluster-randomized trials) itself
  • Blank template for completing the tool, which is currently available in one version
    • Implement RoB 2.0 for cluster-randomized trials when interest is in the effect of assignment to intervention

Available:

  • Background information and detailed guidance for using the RoB 2.0 tool for cross-over trials
  • The tool (cross-over trials) itself
  • Blank template for completing the tool, which has two variants
    • Implement RoB 2.0 for cross-over trials when interest is in the effect of assignment to intervention
    • Implement RoB 2.0 for cross-over trials when the interest is in the effect of starting and adhering to intervention
  • Excel implementation of the tool (cross-over trials) (contains macros)