Table 5.
| a. Sensitivity analysis: comparisons between studies that did and did not perform PE, and by type of outcome reported | |||||
|---|---|---|---|---|---|
| Type of PE result | UHg (µg/L) | Age of exposed | Number of workers | Quality tier | |
| % (number) | Mean (range) | Mean (range)* | Exposed/Controls† | Mean‡ | |
| Performed PE: | 81% (46 of 57 groups) | 212 (11 –1793) | 38 (20–51) | 2480/1244 | 2.0 |
|
| |||||
| Positive results: | 46% (21 of 46 groups) | 403 (50 –1793) | 38 (20–51) | 929/667 | 2.2 |
|
| |||||
| Null results: | 41% (19 of 46 groups) | 104 (11 –672) | 37 (27–43) | 1324/909 | 1.9 |
|
| |||||
| Not reported results: | 13% (6 of 46 groups) | 117 (24 –273) | 41 (35–51) | 227/159 | 1.6 |
|
| |||||
| PE not performed: | 19% (11 of 57 groups) | 60 (12 –301) | 36 (29–44) | 502/475 | NA |
| b. Sensitivity analysis: summary of PE results, UHg, descriptive data, and Tier ratings, stratified by category of exposure | ||||||
|---|---|---|---|---|---|---|
|
| ||||||
|
Exposure Category |
PE Results | UHg (µg/L) | Age of exposed | Number of workers | Quality tier¶ | |
| % with positive results* | Mean (range)† | Mean (range)† | Exposed/Controls‡ | All | (+) | |
| Overall: | 46% (21 of 46 groups) | 205 (11 –1793) | 38 (20 – 51) | 2480/1244 | 2.0 | 2.2 |
|
| ||||||
| HIGH | 79% (15 of 19 groups) | 454 (235 – 1793) | 39 (31 – 51) | 855/533 | 2.2 | 2.4 |
|
| ||||||
| MED | 20% (2 of 10 groups) | 147 (102 – 184) | 35 (20 – 47) | 542/632 | 2.0 | 2.1 |
|
| ||||||
| LOW | 40% (4 of 10 groups) | 65 (50 – 93) | 38 (29 – 51) | 730/686 | 2.0 | 2.0 |
|
| ||||||
| < BEI | 0% (0 of 7 groups) | 24 (11 – 35) | 40 (29 – 47) | 353/309 | 1.5 | NA |
Table summarizes data from 44 studies (57 study groups); data from Albers' case-control study not included.
= Weighted average of group means and range of group means; calculated from data reported for individual study groups.
= When a study reported findings for multiple study groups and results on PE were positive in one or more groups and null in the other(s), the total number of controls in that study was assigned to each relevant Type of PE outcome, as occurred with 2 studies (Smith, and Tang); thus the # of controls listed for "Performed PE" does not agree with the sum of controls listed for Positive, Null, and Not Reported PE results.
= Average of Tier ratings, weighted by study group size (i.e. total number of exposed and controls)
Table summarizes data from 46 groups described in 35 cohort studies; data from Albers' case-control study not included.
= The proportion of study groups with positive findings (i.e. # with ≥1 positive finding on PE divided by # of study groups evaluated using PE).
= Weighted average of group means and (the range of means); calculated from data reported for individual study groups.
= When a study reported findings for multiple study groups, the total number of controls in that study was assigned to each study group that was stratified into a separate exposure category (i.e. Smith 1970, Gunther 1996, and Tang 2006); thus the sum of controls listed across exposure categories does not agree with the Overall sum of controls.
= Average of Quality Tier value weighted by study group size (i.e. total number of exposed and controls) for all study groups evaluated using PE, and those study groups with positive (+) results.
NA = not applicable.