Risk of bias requirements
When a study is entered into the HAWC database for use in an assessment, risk of bias metrics can be entered for a metric of bias for each study. Risk of Bias metrics are organized by domain. The following questions are required for evaluation for this assessment.
Requirements by Study Type
| Domain | Metric | Bioassay | Epidemiology | In Vitro |
|---|---|---|---|---|
| Selection785 | Did selection of study participants result in appropriate comparison groups?1698 | - | ✔ | ✔ |
| Selection785 | Was allocation to study groups adequately concealed?1697 | ✔ | ✔ | ✔ |
| Selection785 | Was administered dose or exposure level adequately randomized?1696 | ✔ | ✔ | ✔ |
| Confounding786 | Did the study design or analysis account for important confounding and modifying variables?1699 | - | ✔ | ✔ |
| Performance787 | Were experimental conditions identical across study groups?1700 | ✔ | - | ✔ |
| Performance787 | Were the research personnel and human subjects blinded to the study group during the study?1701 | ✔ | ✔ | ✔ |
| Attrition788 | Were outcome data complete with respect to attrition or exclusion from analysis?1702 | ✔ | ✔ | ✔ |
| Detection789 | Can we be confident in the exposure characterization?1703 | ✔ | ✔ | ✔ |
| Detection789 | Can we be confident in the outcome assessment?1704 | ✔ | ✔ | ✔ |
| Selective Reporting790 | Were all measured outcomes reported?1705 | ✔ | ✔ | ✔ |
| Other791 | Were there any other potential threats to internal validity?1706 | ✔ | ✔ | ✔ |
Selection785
Was allocation to study groups adequately concealed?1697
Allocation concealment requires that research personnel do not know which administered dose or exposure level is assigned at the start of a study. Human studies also require that allocation be concealed from human subjects prior to entering the study.
Was administered dose or exposure level adequately randomized?1696
Randomization requires that each human subject or animal had an equal chance of being assigned to any study group including controls (e.g., use of random number table or computer generated randomization). Randomization based on body weight also acceptable.
Performance787
Were experimental conditions identical across study groups?1700
Were the research personnel and human subjects blinded to the study group during the study?1701
Blinding requires that study scientists do not know which administered dose or exposure level the human subject or animal is being given (i.e., study group). Human studies also require blinding of the human subjects when possible.
Attrition788
Were outcome data complete with respect to attrition or exclusion from analysis?1702
Attrition rates are required to be similar and uniformly low across groups with respect to withdrawal or exclusion from analysis
Detection789
Can we be confident in the exposure characterization?1703
Confidence requires valid, reliable, and sensitive methods to measure exposure applied consistently across groups.
Can we be confident in the outcome assessment?1704
Confidence requires valid, reliable, and sensitive methods to assess the outcome and the methods should be applied consistently across groups.
Selective Reporting790
Were all measured outcomes reported?1705
Other791
Were there any other potential threats to internal validity?1706
Additional considerations for potential threats to internal validity, e.g., appropriateness of statistical methods, control for litter effects, combining males and females,etc.
Selection785
Did selection of study participants result in appropriate comparison groups?1698
Comparison group appropriateness refers to having similar baseline characteristics between the groups aside from the exposures and outcomes under study.
Was allocation to study groups adequately concealed?1697
Allocation concealment requires that research personnel do not know which administered dose or exposure level is assigned at the start of a study. Human studies also require that allocation be concealed from human subjects prior to entering the study.
Was administered dose or exposure level adequately randomized?1696
Randomization requires that each human subject or animal had an equal chance of being assigned to any study group including controls (e.g., use of random number table or computer generated randomization). Randomization based on body weight also acceptable.
Confounding786
Did the study design or analysis account for important confounding and modifying variables?1699
Performance787
Were the research personnel and human subjects blinded to the study group during the study?1701
Blinding requires that study scientists do not know which administered dose or exposure level the human subject or animal is being given (i.e., study group). Human studies also require blinding of the human subjects when possible.
Attrition788
Were outcome data complete with respect to attrition or exclusion from analysis?1702
Attrition rates are required to be similar and uniformly low across groups with respect to withdrawal or exclusion from analysis
Detection789
Can we be confident in the exposure characterization?1703
Confidence requires valid, reliable, and sensitive methods to measure exposure applied consistently across groups.
Can we be confident in the outcome assessment?1704
Confidence requires valid, reliable, and sensitive methods to assess the outcome and the methods should be applied consistently across groups.
Selective Reporting790
Were all measured outcomes reported?1705
Other791
Were there any other potential threats to internal validity?1706
Additional considerations for potential threats to internal validity, e.g., appropriateness of statistical methods, control for litter effects, combining males and females,etc.
Selection785
Did selection of study participants result in appropriate comparison groups?1698
Comparison group appropriateness refers to having similar baseline characteristics between the groups aside from the exposures and outcomes under study.
Was allocation to study groups adequately concealed?1697
Allocation concealment requires that research personnel do not know which administered dose or exposure level is assigned at the start of a study. Human studies also require that allocation be concealed from human subjects prior to entering the study.
Was administered dose or exposure level adequately randomized?1696
Randomization requires that each human subject or animal had an equal chance of being assigned to any study group including controls (e.g., use of random number table or computer generated randomization). Randomization based on body weight also acceptable.
Confounding786
Did the study design or analysis account for important confounding and modifying variables?1699
Performance787
Were experimental conditions identical across study groups?1700
Were the research personnel and human subjects blinded to the study group during the study?1701
Blinding requires that study scientists do not know which administered dose or exposure level the human subject or animal is being given (i.e., study group). Human studies also require blinding of the human subjects when possible.
Attrition788
Were outcome data complete with respect to attrition or exclusion from analysis?1702
Attrition rates are required to be similar and uniformly low across groups with respect to withdrawal or exclusion from analysis
Detection789
Can we be confident in the exposure characterization?1703
Confidence requires valid, reliable, and sensitive methods to measure exposure applied consistently across groups.
Can we be confident in the outcome assessment?1704
Confidence requires valid, reliable, and sensitive methods to assess the outcome and the methods should be applied consistently across groups.
Selective Reporting790
Were all measured outcomes reported?1705
Other791
Were there any other potential threats to internal validity?1706
Additional considerations for potential threats to internal validity, e.g., appropriateness of statistical methods, control for litter effects, combining males and females,etc.