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Table 5 Cochrane risk of bias table

From: Mindfulness-based interventions in epilepsy: a systematic review

 

Thompson et al. (2010) [34]

Thompson et al. (2015) [35]

Tang et al. (2015) [36]

Entry

Judgement

Support for judgement

Judgement

Support for judgement

Judgement

Support for judgement

Random sequence generation (selection bias)

Unclear Risk

Quote: “Using a stratified randomized, crossover design we randomly assigned participants to one of four strata.”

Randomisation method is not described

Unclear Risk

Quote: “Using a stratified randomized, crossover design we randomly assigned participants to one of four strata.”

Randomisation procedure not described

Low Risk

Quote: “Simple randomization by drawing was performed within each block to assign patients to one of the groups alternatively”

Random allocation

Allocation concealment (selection bias)

Unclear Risk

Unclear whether participants/assessors could have been aware of allocation to intervention/control in advance

High Risk

Quote: “…within each condition, people who required a particular mode of delivery (web or telephone) were placed in that group and the remainder (the majority of participants) were assigned to equalise the groups.”

Not described, appears patients were allocated to different interventions (web or telephone) based on preference/need

Unclear Risk

Quote: “randomization was performed by an independent research assistant”

Randomization performed by independent research assistant but method of concealment not explained.

Blinding of participants and personnel (performance bias)

High Risk

Quote: “Neither the participants nor the project staff were blinded to the group assignment.”

Clearly stated in paper under 2.5.3 Recruitment that neither were blinded

High Risk

Not described, and as above participants could choose to receive telephone or web delivery.

Low Risk

Quote: “A team of trained research assistants…who were blinded to participants’ intervention group performed all assessments…”

The assessors were blinded to the patient’s intervention grouping.

Blinding of outcome assessment (detection bias)

High Risk

Quote: “Neither the participants nor the project staff were blinded to the group assignment.”

Clearly stated in paper under 2.5.3 Recruitment that neither were blinded

Unclear Risk

Not described

Low Risk

Quote: “…team of trained research assistants with a bachelor’s degree in psychology who were blinded to participants’ intervention group performed all assessments; they were separated into 2 teams, one for baseline assessment and the other for post intervention assessment.”

Incomplete outcome data addressed (attrition bias)

High Risk

Due to repeated measures design only participants completing interim assessments were included in analyses.

13 participants left the study, not clear if control or intervention.

Missing data not described

Unclear Risk

Attrition poorly characterised. Attendance poorly described including reasons for not attending.

Missing values were imputed, but levels of missing values were not described. However intention-to-treat analysis carried out according to participants’ original treatment assignment.

Low Risk

Missing outcome data balanced in numbers across intervention groups.

Selective reporting (reporting bias

Unclear Risk

All outcomes appear to have been reported, however no protocol.

Unclear Risk

Primary outcome not defined and poor discussion of four of six main outcomes (DCSE, SC, Physical and mental health QoL). No protocol.

Low Risk

Full study protocol is available

Other Bias

Unclear Risk

 

Unclear Risk

 

Low Risk

No other sources of bias