Table 1.
Bias domain | Criteria | Risk of bias |
---|---|---|
A. Selection bias | Random sampling, areas selected based on noise exposure, response rate,a inclusion criteria not contingent on sleep and health conditions | Low |
a. response rate,a or b. Non-random sampling, or c. Sampling not based on noise exposure, or d. Individuals were excluded based on sleep and health criteria |
High | |
Insufficient information to make a judgment | Unclear | |
B. Information bias (exposure assessment) | a. Based on measurements for at least 1 wk, or b. Based on a noise map that was verified by noise measurements, or c. Based on a noise map that was based on actual traffic data |
Low |
a. Based on measurements of , or measurements were not continuous, or b. Based on a noise map that was not verified by noise measurements, or the predictions were not based on actual traffic data |
High | |
Insufficient information to make a judgment | Unclear | |
C. Bias due to confounding | All most-important confounders accounted for in analysis | Low |
No accounting for important confounders | High | |
Insufficient information to make a judgment | Unclear | |
D. Reporting bias | Complete reporting of all outcomes analyzed including nonsignificant results | Low |
Not all outcomes reported, underreporting methods or statistical analysis, not reporting conflicts of interest | High | |
Insufficient information to make a judgment | Unclear |
Note: WHO, World Health Organization.
aThe 50% response rate criterion was based on recommendations for cross-sectional studies by the National Institutes of Health.38