Table 1 Guidelines for quality assessment of included trials [7, 31,32,33,34,35,36,37, 63]

Patient blinding [39]:

Was knowledge of the allocated intervention adequately prevented during the study?

“Blinding of patients is a must when outcomes are subjective or self-reported. When Outcomes are measured by an assessor, then assessors should be blinded to group allocation. When Outcomes are automated (there is no assessor involved) then, blinding of participants or assessors is not an issue.”

Any one of the following:

No blinding or incomplete blinding, but the review authors judge that the outcome is not likely to be influenced by lack of blinding (Automated outcome or administrative); Blinding of participants and key study personnel ensured, and unlikely that the blinding could have been broken; Objectives automatized outcomes coming from databases or hospital register office.

Any one of the following:

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

Blinding of key study participants and personnel attempted, but likely that the blinding could have been broken, and the outcome is likely to be influenced by lack of blinding.

Any one of the following:

Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’;

The study did not address the issue of blinding.

Blinded therapist/care-provider

The study describes in the title, abstract, or text that the therapists/care-providers were blinded. The blinding was appropriate.

The study describes in the title, abstract, or text that the therapists/care-providers were not blinded, or because of the nature of the intervention (e.g., exercise prescription or supervision, etc.), the therapist could not be blinded.

There is insufficient information to permit a judgment.

Blinded principal-investigator

The study describes in the title, abstract, or text that the investigator was blinded. The blinding was appropriate.

The study describes in the title, abstract, or text that the investigator was not blinded.

There is insufficient information to permit a judgment.

Blinded statistician

The study describes in the title, abstract, or text that the statistician was blinded. The blinding was appropriate.

The study describes in the title, abstract, or text that the statistician was not blinded.

There is insufficient information to permit a judgment.

Assessor blinding [39]:

Was knowledge of the allocated intervention adequately prevented during the study?

Detection bias due to knowledge of the allocated interventions by outcome assessors.

Any one of the following:

No blinding of outcome assessment, but the review authors judge that the outcome measurement is not likely to be influenced by lack of blinding;

Blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.

Any one of the following:

No blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding;

Blinding of outcome assessment, but likely that the blinding could have been broken and the outcome measurement is likely to be influenced by lack of blinding.

Any one of the following:

Insufficient information to permit judgement of ‘Low risk’ or ‘High risk’;

The study did not address the issue of blinding.

Blinding of both patients and assessors) [39]

Both patient blinding and assessor blinding were judged as having low risk of bias.

Both patient blinding and assessor blinding were judged as having high risk of bias

Both patient blinding and assessor blinding were judged as having unclear risk of bias.

Study described as double blind

“Double blind” is the description in the study related to “blindness.”

Also, it should be stated that neither the person doing the assessments nor the study participants could identify the intervention being assessed.

Not described as double blind.

There is insufficient information to permit a judgment.

blinding of patients, assessors, and caregivers concurrently

Both patient blinding and assessor blinding were judged as having low risk of bias. Also, care-providers are blinded.

Both patient blinding and assessor blinding were judged as having high risk of bias. Also, care-providers are not blinded.

Both patient blinding and assessor blinding were judged as having unclear risk of bias. Also, care-providers are judged as “unclear”.

The method of blinding was appropriate

The authors use the blinding method appropriately.

Blinding of participants/patients is a “must” when outcomes are subjective or self-reported.

When outcomes are measured by an assessor, the assessors should be blinded to group allocation.

Also, score “completely done” when it is unlikely that the blinding could have been broken and the nonblinding of others is unlikely to introduce bias. No blinding, but the review authors judge that the outcome and the outcome measurement are not likely to be influenced by lack of blinding. Objectives automatized outcomes coming from databases or hospital register office.

There is no blinding or incomplete blinding is performed, and the outcome or outcome measurement is likely to be influenced by lack of blinding.

There is insufficient information to permit a judgment.