1. Was the allocation sequence randomly generated?

• Yes, low risk of bias

• • A random (unpredictable) assignment sequence

  • Examples of adequate methods of sequence generation are computer‐generated random sequence, coin toss (for studies with two groups), rolling a dice (for studies with two or more groups), drawing of balls of different colours, dealing previously shuffled cards

• No, high risk of bias

• • Quasi‐randomised approach: examples of inadequate methods are: alternation, birth date, social insurance/security number, date in which they are invited to participate in the study, and hospital registration number

  • Non‐random approaches: allocation by judgement of the clinician; by preference of the participant; based on the results of a laboratory test or a series of tests

• Unclear

• • Insufficient information about the sequence generation process to permit judgement

2. Was the treatment allocation adequately concealed?

• Yes, low risk of bias

• • Assignment must be generated independently by a person not responsible for determining the eligibility of the participants. This person has no information about the people included in the study and has no influence on the assignment sequence or on the decision about whether the person is eligible to enter the trial. Examples of adequate methods of allocation concealment are: central allocation, including telephone, web‐based and pharmacy‐controlled randomisation; sequentially numbered drug containers of identical appearance; sequentially numbered, opaque sealed envelopes

• No, high risk of bias

• • Examples of inadequate methods of allocation concealment are: alternate medical record numbers, unsealed envelopes; date of birth; case record number; alternation or rotation; an open list of random numbers any information in the study that indicated that investigators or participants could influence the intervention group

• Unclear

• • Randomisation stated but no information on method of allocation used is available

3. Blinding ‐ Was knowledge of the allocated interventions adequately prevented during the study?

Was the participant blinded to the intervention?

• Yes, low risk of bias

• • The treatment and control groups are indistinguishable for the participants or if the participant was described as blinded and the method of blinding was described

• No, high risk of bias

• • Blinding of study participants attempted, but likely that the blinding could have been broken; participants were not blinded, and the non‐blinding of others likely to introduce bias

• Unclear

Was the care provider blinded to the intervention?

• Yes, low risk of bias

• • The treatment and control groups are indistinguishable for the care/treatment providers or if the care provider was described as blinded and the method of blinding was described

• No, high risk of bias

• • Blinding of care or treatment providers attempted, but likely that the blinding could have been broken; care or treatment providers were not blinded, and the non‐blinding of others likely to introduce bias

• Unclear

Was the outcome assessor blinded to the intervention?

• Yes, low risk of bias

• • Adequacy of blinding should be assessed for the primary outcomes. The outcome assessor was described as blinded and the method of blinding was described

• No, high risk of bias

• • No blinding or incomplete blinding, and the outcome or outcome measurement is likely to be influenced by lack of blinding

• Unclear

4. Were incomplete outcome data adequately addressed?

Was the dropout rate described and acceptable?

The number of participants who were included in the study but did not complete the observation period or were not included in the analysis must be described and reasons given

• Yes, low risk of bias

• • No missing outcome data

  • Reasons for missing outcome data unlikely to be related to true outcome (for survival data, censoring unlikely to be introducing bias)

  • Missing outcome data balanced in numbers across intervention groups, with similar reasons for missing data across groups

  • Missing data have been imputed using appropriate methods such as intention‐to‐treat analysis

• No, high risk of bias

• • Lack of appropriate measures to handle missing data

  • Reason for missing outcome data likely to be related to true outcome, with either imbalance in numbers or reasons for missing data across intervention groups

• Unclear

5. Are reports of the study free of suggestion of selective outcome reporting?

• Yes, low risk of bias

• • If all the results from all prespecified outcomes have been adequately reported in the published report of the trial. This information is either obtained by comparing the protocol and the final trial report, or in the absence of the protocol, assessing that the published report includes enough information to make this judgement. We will identify the study protocols from the registries as listed under Electronic searches. Alternatively, a judgement could be made if the study report lists the outcomes of interest in the methods of the study and then reports all these outcomes in the results section of the study report.

• No, high risk of bias

• • Not all of the study's prespecified primary outcomes have been reported

  • One or more primary outcomes is reported using measurements, analysis methods or subsets of the data (e.g. subscales) that were not prespecified

  • One or more reported primary outcomes were not prespecified (unless clear justification for their reporting is provided, such as an unexpected adverse effect)

  • One or more outcomes of interest in the review are reported incompletely so that they cannot be entered in a meta‐analysis

  • The study report fails to include results for a key outcome that would be expected to have been reported for such a study

• Unclear

6. Other sources of potential bias

Were the groups similar at baseline regarding the most important prognostic indicators?

• Groups have to be similar at baseline regarding demographic factors, duration and severity of complaints. Alternatively if there were imbalances at baseline these have been accounted for in the analysis of the study.

Were co‐interventions avoided or similar?

• There were no co‐interventions or there were co‐interventions but they were similar between the treatment and control groups.

Was compliance acceptable in all groups?

• The review author determines whether compliance with interventions is acceptable, based on the reported intensity, duration, number and frequency of sessions for both the treatment intervention and control intervention(s). For example, ultrasound treatment is usually administered over several sessions; therefore, it is necessary to assess how many sessions each participant attended or if participants completed the course of an oral drug therapy.

Were the studies or investigators in receipt of financial support from agencies or organisations with a financial interest in the outcome of the study?

Was the study free of other issues, for instance, design‐specific risks of bias such as recruitment in cluster for cluster‐RCT and block randomisation of unblinded studies?