Table 4 Criteria for assessing the overall risk of bias for individual studies
Risk of bias level | Explanation |
|---|---|
Overall low risk of bias | The study is considered to have low risk of bias for all risk-of-bias criteria for the findings |
Overall medium risk of bias | The study is considered to have medium risk of bias in at least one risk-of-bias criterion, but not to have high or unclear risk of bias for any risk-of-bias-criteria for the findings |
Overall high risk of bias | The study is considered to have high risk of bias in at least one risk-of-bias criterion for the findings |
Overall unclear risk of bias | The study is considered to have unclear risk of bias when the reported information is insufficient to assess the risk of bias for at least one criterion, and the risk is judged to be lower than "high" for all other criteria |