Aspect of trial bias assessed | Type of risk of bias in trial and clarification |
---|---|
1. Random sequence generation | Selection bias |
2. Allocation concealment | Selection bias |
3. Blinding of participants and personnel | Performance bias |
4a. Blinding of outcome assessment - subjective outcomes | Detection bias; e.g. depression symptoms measured on a standardized self-report questionnaire |
4b. Blinding of outcome assessment - objective outcomes | Detection bias; e.g. depression remission measured by a structured clinical interview |
5. Incomplete outcome data | Attrition bias |
6. Selective reporting | Reporting bias |
7. Other bias | e.g. when bias may seriously alter the results, such as improper adjustment for baseline imbalances or funding bias |