Table 1.

Key study evaluation questions to determine the level of certainty ratings for health outcomes.

Study Evaluation Questions
Population and Sample
1. Does the control group match the exposed group?
2. Is the sample generalizable to the population of interest?
3. Did the study a priori quantify sample and power?
4. Were missing data addressed and tested?
Exposure
5. Was exposure directly measured and quantified?
6. Was the exposure or proxy/surrogate of exposure measured from a point location?
7. Does the proxy/surrogate adequately estimate exposure?
8. Was there a temporal relationship between exposure and outcome?
Health Outcomes
9. Was the health outcome determined by a medical provider?
10. Was a dose-response relationship seen in any outcome?
Confounders
11. Did the study design or analysis account for important confounding and modifying variables?
12. Did the study design or analysis adjust or control for other environmental exposures that were anticipated to bias results?
13. Were sensitivity analyses attempted for population, outcome, or exposure?
Reporting
14. Did the study conclusions match the results?
Final level of certainty rating: Low/Moderate/High