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Random sequence generation |
Criteria for judgment of “low risk” of bias | The articles that appropriately described the method of randomization |
Criteria for judgment of “high risk” of bias | Articles that presented a methodological failure in the randomization criterion or the difficult reproducibility method |
Criteria for judgment of “unclear risk” of bias | When the articles did not describe the method of randomization |
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Allocation concealment |
Criteria for judgment of “low risk” of bias | When the allocation sequences of samples were concealed in the randomization |
Criteria for judgment of “high risk” of bias | When the sequences of allocation of samples were not concealed at randomization |
Criteria for judgment of “unclear risk” of bias | When the allocation sequences were unreported |
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Blinding of participants and researchers |
Criteria for judgment of “low risk” of bias | When the sample was blind |
Criteria for judgment of “high risk” of bias | If the methodology could not be blinded for whatever reason (sample/appraiser) |
Criteria for judgment of “unclear risk” of bias | When the sample was not reported either way |
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Blinding of outcome assessment |
Criteria for judgment of “low risk” of bias | When the evaluators reported that the blinding in the evaluation was effective |
Criteria for judgment of “high risk” of bias | If the study informed the evaluators how the blinding was done |
Criteria for judgment of “unclear risk” of bias | When the blinding was not reported |
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Incomplete outcome data |
Criteria for judgment of “low risk” of bias | When there was an exhaustive description of the main data |
Criteria for judgment of “high risk” of bias | If there was a loss due to an incomplete description of the main results regardless of quantity, nature, and manipulation |
Criteria for judgment of “unclear risk” of bias | When the results were not reported |
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Selective reporting |
Criteria for judgment of “low risk” of bias | When the discussion excluded some of the results |
Criteria for judgment of “high risk” of bias | When the article discussed the data completely |
Criteria for judgment of “unclear risk” of bias | When the organization of the results in the discussion was unclear |
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