Enable Risk of Bias 2

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Enable RoB 2 


Start by reading the information on the Cochrane risk of bias tool Risk of Bias 2 (RoB 2) available from Cochrane Methods.

Please note the following important points:

  • RoB 2 is only available for intervention reviews.
  • The setup for RoB 2 is not customisable.
  • If a review does not have any included studies, RoB 2 should not be enabled, otherwise it will show an empty risk of bias table when published.
  • Covidence is not currently set up to make RoB 2 assessments (relevant to Cochrane reviews only). 

The Cochrane risk of bias tool RoB2 can only be enabled for intervention reviews. To enable it, open your review in RevMan and go to the 'Review criteria' section > select the 'risk of bias' tab > click on 'Enable RoB 2'. If you have any questions, please contact support@cochrane.org.  

We advise that this is after you have input your results data and have completed your risk of bias assessments using the tools developed to manage the process (see the 'Tools' section in the RoB 2 Cochrane Review Starter Pack – available via Cochrane Methods).

RoB 2 is an updated version of the Cochrane risk of bias tool. The main differences are:

  • Each domain has a set of questions to help you decide if there is bias or not.
  • You assess bias for specific results within an RCT, rather than for the RCT as a whole.
  • Algorithms embedded in the tool propose judgements.
  • There is an overall bias decided across all the domains for each result.  

Information for Cochrane authors 

Cochrane reviews that have already begun peer review should not switch to RoB 2 unless advised to do so by the editors. If you have any questions, please contact support@cochrane.org.  

Cochrane authors and Cochrane group staff can submit RoB 2 questions to the monthly Methods Support Unit Web Clinic for discussion. Read more and submit questions here.

Considerations for Cochrane authors before enabling RoB 2:

  • If you are working with a Cochrane Review Group, you may wish to share your completed risk of bias assessments in the RoB 2 Excel tool with your group for checking, before you enter the RoB 2 assessments into RevMan.
  • For review updates that have switched to RoB 2, all risk of bias data from the previous version will be lost when RoB 2 is enabled. If you need to download or make a copy, ensure to do it before RoB 2 is enabled. Read more about tagging a version or exporting a copy of your data.
  • Once RoB 2 is enabled, it is only possible to disable it by reverting the full review to a version before it was enabled. Read further instructions about reverting to a previous version.

In most circumstances, authors do not need to create any risk of bias tables or figures outside of RevMan. We recommend authors visualise RoB 2 data in a Cochrane Review by:

Both of these are created in RevMan.

Note the domains of the RoB 2 tool

The domains will now include the ones covered by the RoB 2 tool. Note that the first domain 'Bias arising from the randomization process' is study-level, while all others are outcome-level.

Also, note that all the domains are fixed and you cannot edit them, which is different from the risk of bias 1 setup.

ROBINS-I is not currently supported by RevMan. ROBINS-I needs to be included in an additional table, with figures created using the ROBINS-I data visualisation tool, not the RoB2 tool.