Table 1.
Description of tools used to assess risk of bias
| Program or agency | Tool | Assessment process | Domains assessed | Number of questions | Available answer options |
|---|---|---|---|---|---|
| NTP | OHAT | Risk of bias, internal validity | Selection bias | 1 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB |
| Confounding bias | 1 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB | |||
| Attrition/exclusion bias | 1 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB | |||
| Detection bias | 2 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB | |||
| Selective bias reporting bias | 1 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB | |||
| Other bias | 1 | Definitely low ROB; probably low ROB; probably high ROB; definitely high ROB | |||
| EPA | IRIS | Study evaluation | Exposure measurement | 1 | Good; adequate; deficient; critically deficient |
| Outcome ascertainment | 1 | Good; adequate; deficient; critically deficient | |||
| Participant selection | 1 | Good; adequate; deficient; critically deficient | |||
| Confounding | 1 | Good; adequate; deficient; critically deficient | |||
| Analysis | 1 | Good; adequate; deficient; critically deficient | |||
| Selective reporting | 1 | Good; adequate; deficient | |||
| Sensitivity | 1 | Adequate; deficient | |||
| Overall study confidence | 1 | High; medium; low; uninformative | |||
| EPA | TSCA | Data quality criteria for epidemiological studies | Study population | 3 | High; medium; low; unacceptable |
| Exposure characterization | 3 | High; medium; low; unacceptable | |||
| Outcome assessment | 2 |
High; medium; low; unacceptable* *Unacceptable not available for one question |
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| Potential confounding/variable control | 3 |
High; medium; low; unacceptable* *High and unacceptable not available for one question |
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| Analysis | 4 |
High; medium; low; unacceptable* *High and low not available for two questions *High and unacceptable not available for two questions |
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| Biomarker selection and measurement | 7 |
High; medium; low; unacceptable *High and unacceptable not available for one question *Unacceptable not available for three questions |
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| Overall study confidence | 1 | Sum of weighted scores/sum of metric weighting factor | |||
| UCSF | Navigation Guide | Risk of bias, internal validity | Source population representation | 1 | Low; probably low; probably high; high |
| Blinding | 1 | Low; probably low; probably high; high | |||
| Exposure assessment | 1 | Low; probably low; probably high; high | |||
| Outcome assessment | 1 | Low; probably low; probably high; high | |||
| Incomplete outcome data | 1 | Low; probably low; probably high; high | |||
| Selective outcome reporting | 1 | Low; probably low; probably high; high | |||
| Confounding | 1 | Low; probably low; probably high; high | |||
| Conflicts of interest | 1 | Low; probably low; probably high; high | |||
| Other | 1 | Low; probably low; probably high; high |
Abbreviations: NTP National Toxicology Program, OHAT, Office of Health Assessment and Translation, EPA, Environmental Protection Agency, IRIS Integrated Risk Information System, TSCA Toxic Substances Control Act; ROB risk of bias, UCSF, University of California, San Francisco