Domain	Review authors’ judgement	Support for judgement
Random sequence generation*	High risk Unclear Low risk	Describe the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups. Quasi‐RCTs and Controlled Before and After (CBA) studies must be rated as ‘High Risk’ for random sequence generation as the methods were not, by definition, truly random.
Allocation concealment	High risk Unclear Low risk	Describe the method used to conceal the allocation sequence in sufficient detail to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment. CBA Studies should be rated ‘High Risk. Quasi‐RCTs are likely to be rated ‘High Risk but there may be some exceptions.
Blinding of participants and personnel Assessments should be made for each main outcome (or class of outcomes).	High risk Unclear Low risk	Describe all measures used, if any, to blind study participants and personnel from knowledge of which intervention a participant received. Provide any information relating to whether the intended blinding was effective.
Blinding of outcome assessment Assessments should be made for each main outcome (or class of outcomes).	High risk Unclear Low risk	Describe all measures used, if any, to blind outcome assessors from knowledge of which intervention a participant received. Provide any information relating to whether the intended blinding was effective. If the outcome is objective (eg. length of hospital stay) the rating should be ‘Low risk.
Incomplete outcome data Assessments should be made for each main outcome (or class of outcomes).	High risk Unclear Low risk	Describe the completeness of outcome data for each main outcome, including attrition and exclusions from the analysis. State whether attrition and exclusions were reported, the numbers in each intervention group (compared with total randomized participants), reasons for attrition/exclusions where reported, and any re‐inclusions in analyses performed by the review authors.
Selective reporting	High risk Unclear Low risk	State how the possibility of selective outcome reporting was examined by the review authors, and what was found.
Other sources of bias See the Cochrane Handbook 8.15.1 for further examples of potential threats to validity, as well as 16.3.2 for issues relating to cluster trials and 16.4.3 for cross‐over trials.	Note: all answers should follow the format: High risk Unclear Low risk	State any important concerns about bias not addressed in the other domains in the tool. If particular questions/entries were pre‐specified in the review’s protocol, responses should be provided for each question/entry.