Table 3.
Risk of Bias in each trial
| Study | Random Sequence | Allocation Concealment | Blinding Participants | Blinding Outcome | Incomplete Outcome | Selective Reporting | Attention Bias |
|---|---|---|---|---|---|---|---|
| Herring et al., 2012 [35] | Blocked randomisation stratified according to medication use. | Clinicians performing the initial assessment blinded to allocation | Participants not blinded X | Not blinded. X | All allocated subjects completed the study. | All outcomes were reported. | Low intensity and high intensity groups matched for therapist time but not waiting list control group. |
| Jazaieri et al., 2012 [34] | Randomised using Efrons randomisation procedure | No information (?) | Participants not blinded (X) | No information regarding assessor blinding (?) | No difference in attrition between groups. | Patients self-reported the quantity of exercise performed. (?) | patients were not matched for time spent with an instructor. (X) |
| Smits et al. 2008 [36] | Computer Generated Random Sequence | No allocation concealment (X) | Participants were not blinded (X) | . Not blinded. (X) | No difference in attrition between groups. | All outcomes were reported. | Attention bias, patients were not matched for the spent with an instructor. (X) |
| Merom et al. 2007 [23] | Computer Generated Randomisation | Performed by independent research centre | Participants not blinded (X) | Not Blinded (X) | No difference in attrition between groups. | All outcomes were reported. | Groups had matched time with therapist. |
| Mailey et al., 2010 [37] | No information about method of randomisation (?) | No information (?) | Participants not blinded (X) | Not blinded (?) | Very little attrition in both groups. | All outcomes were reported. | Intervention and control groups not matched for time (X) |
| Broman-Fulks, 2008 [33] | No information about the method of randomisation (?) | No information (?) | Participants were blinded as to the group they were in | Not Blinded (X) | All allocated subjects completed the study. | All outcomes were reported. | Attention bias, patients were not matched for the spent with an instructor. (X) |
| Wedekind 2010 [38] | Blocked randomisation | Allocation performed by the hospital pharmacist | Participants not blinded (X) | Blind rater used to eliminate expectation differences (?) | No significant difference in drop outs between groups. | All outcomes were reported. | Subjects in the control group received time with a therapist doing relaxation training. |
| Brooks et al. 1998 [39] | No information about method of randomisation (?) | No information (?) | Participants were blinded. | Investigators were blinded | Similar attrition rate | All outcomes were reported. | Time matched with therapist across groups |
| Villaverde et al. 2012 [40] | Details given regarding the randomisation procedure | No information (?) | Participants not blinded (X) | Not Blinded (X) | Similar attrition rate between groups. | All outcomes were reported. | No time matching between groups (X) |
| Medina et al. 2015 [41] | Not mentioned in the method section. (X) | No information (?) | Participants not blinded (X) | Not Blinded (X) | Similar attrition rate | All outcomes were reported. | No time matching between groups (X) |
| Broman-Fulks, 2004 [43] | No information about method of randomisation (X) | No information (?) | Participants not blinded (X) | Not Blinded (X) | No attrition in the groups | All outcomes were reported. | Matched for time |
| Sexton et al. 1989 [44] | No information about the method of randomisation (?) | No information (?) | Participants not blinded (X) | Not Blinded (X) | higher no. of dropout in the high intensity group (X) | All outcomes were reported. | Less risk of attention bias as both active interventions. |
| Steptoe et al. 1989 [45] | No information about the method of randomisation (?) | No information (?) | Participants not blinded (X) | Not Blinded (X) | Similar attrition rate between groups. | Some outcomes were not reported (?) | Participants in both groups had similar time with therapists |
| Gaudlitz et al. 2015 [46] | Randomised using block allocation | Assessment staff were blinded | Participants were blinded as to nature of the study | Study staff were blinded | Low attrition rate and all subjects accounted for | All outcomes were reported. | Time matched with therapist across groups |
| Martinsen et al., 1989 [42] | Randomised using block allocation | No information (?) | Participants not blinded (X) | Assessors were not blinded | Low attrition rate | All outcomes were reported. | Groups were time matched |