Revised Cochrane risk-of-bias tool for randomized trials (RoB 2)
SHORT VERSION (CRIBSHEET)
Edited by Julian PT Higgins, Jelena Savović, Matthew J Page, Jonathan AC Sterne
on behalf of the RoB 2 Development Group
Version of 22 August 2019
The development of the RoB 2 tool was supported by the MRC Network of Hubs for Trials Methodology Research (MR/L004933/2- N61), with the support of the
host MRC ConDuCT-II Hub (Collaboration and innovation for Difficult and Complex randomised controlled Trials In Invasive procedures - MR/K025643/1), by MRC
research grant MR/M025209/1, and by a grant from The Cochrane Collaboration.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
1
,Preliminary considerations
Study design
Individually-randomized parallel-group trial
Cluster-randomized parallel-group trial
Individually randomized cross-over (or other matched) trial
For the purposes of this assessment, the interventions being compared are defined as
Experimental: Comparator:
Specify which outcome is being assessed for risk of bias
Specify the numerical result being assessed. In case of multiple alternative
analyses being presented, specify the numeric result (e.g. RR = 1.52 (95% CI
0.83 to 2.77) and/or a reference (e.g. to a table, figure or paragraph) that
uniquely defines the result being assessed.
Is the review team’s aim for this result…?
to assess the effect of assignment to intervention (the ‘intention-to-treat’ effect)
to assess the effect of adhering to intervention (the ‘per-protocol’ effect)
If the aim is to assess the effect of adhering to intervention, select the deviations from intended intervention that should be addressed (at least one must be
checked):
occurrence of non-protocol interventions
failures in implementing the intervention that could have affected the outcome
non-adherence to their assigned intervention by trial participants
2
, Which of the following sources were obtained to help inform the risk-of-bias assessment? (tick as many as apply)
Journal article(s)
Trial protocol
Statistical analysis plan (SAP)
Non-commercial trial registry record (e.g. ClinicalTrials.gov record)
Company-owned trial registry record (e.g. GSK Clinical Study Register record)
“Grey literature” (e.g. unpublished thesis)
Conference abstract(s) about the trial
Regulatory document (e.g. Clinical Study Report, Drug Approval Package)
Research ethics application
Grant database summary (e.g. NIH RePORTER or Research Councils UK Gateway to Research)
Personal communication with trialist
Personal communication with the sponsor
3
SHORT VERSION (CRIBSHEET)
Edited by Julian PT Higgins, Jelena Savović, Matthew J Page, Jonathan AC Sterne
on behalf of the RoB 2 Development Group
Version of 22 August 2019
The development of the RoB 2 tool was supported by the MRC Network of Hubs for Trials Methodology Research (MR/L004933/2- N61), with the support of the
host MRC ConDuCT-II Hub (Collaboration and innovation for Difficult and Complex randomised controlled Trials In Invasive procedures - MR/K025643/1), by MRC
research grant MR/M025209/1, and by a grant from The Cochrane Collaboration.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
1
,Preliminary considerations
Study design
Individually-randomized parallel-group trial
Cluster-randomized parallel-group trial
Individually randomized cross-over (or other matched) trial
For the purposes of this assessment, the interventions being compared are defined as
Experimental: Comparator:
Specify which outcome is being assessed for risk of bias
Specify the numerical result being assessed. In case of multiple alternative
analyses being presented, specify the numeric result (e.g. RR = 1.52 (95% CI
0.83 to 2.77) and/or a reference (e.g. to a table, figure or paragraph) that
uniquely defines the result being assessed.
Is the review team’s aim for this result…?
to assess the effect of assignment to intervention (the ‘intention-to-treat’ effect)
to assess the effect of adhering to intervention (the ‘per-protocol’ effect)
If the aim is to assess the effect of adhering to intervention, select the deviations from intended intervention that should be addressed (at least one must be
checked):
occurrence of non-protocol interventions
failures in implementing the intervention that could have affected the outcome
non-adherence to their assigned intervention by trial participants
2
, Which of the following sources were obtained to help inform the risk-of-bias assessment? (tick as many as apply)
Journal article(s)
Trial protocol
Statistical analysis plan (SAP)
Non-commercial trial registry record (e.g. ClinicalTrials.gov record)
Company-owned trial registry record (e.g. GSK Clinical Study Register record)
“Grey literature” (e.g. unpublished thesis)
Conference abstract(s) about the trial
Regulatory document (e.g. Clinical Study Report, Drug Approval Package)
Research ethics application
Grant database summary (e.g. NIH RePORTER or Research Councils UK Gateway to Research)
Personal communication with trialist
Personal communication with the sponsor
3
