Table 4.
Models evaluating the persistence of the lead-associated cognitive effects, Baltimore Memory Study, 2001-2005.
| Mean (95% CI) domain score difference with 12.7 μg/g tibia lead difference2 | Joint test1 | ||||
|---|---|---|---|---|---|
| Domain | Base Model3 | SES-adjusted3 | Race-adjusted3 | Race- and SES-adjusted3 | p-value |
| All subjects, N = 964 | |||||
| Language | -0.1207 (-0.1829, -0.0584) | -0.0254 (-0.0752, 0.0244) | -0.0127 (-0.065, 0.0396) | 0.0216 (-0.0232, 0.0664) | 0.5 |
| Processing speed | -0.0851 (-0.1523, -0.0179) | -0.0254 (-0.0901, 0.0393) | -0.0127 (-0.0774, 0.052) | 0.0064 (-0.0584, 0.0711) | 0.88 |
| Executive functioning | -0.1219 (-0.1667, -0.0771) | -0.0622 (-0.1045, -0.0199) | -0.0483 (-0.0881, -0.0084) | -0.0305 (-0.0678, 0.0069) | 0.26 |
| Verbal memory & learning | -0.1359 (-0.1981, -0.0737) | -0.0737 (-0.1334, -0.0139) | -0.061 (-0.1232, 0.0013) | -0.0406 (-0.1029, 0.0216) | 0.16 |
| Visual memory | -0.1207 (-0.1754, -0.0659) | -0.0622 (-0.117, -0.0075) | -0.0495 (-0.1043, 0.0052) | -0.0318 (-0.0865, 0.023) | 0.21 |
| African-American subjects only, N = 394 | |||||
| Language | 0.0495 (-0.0376, 0.1367) | 0.0648 (-0.0099, 0.1394) | NA | NA | 0.23 |
| Processing speed | 0.0076 (-0.082, 0.0972) | 0.0216 (-0.0680, 0.1112) | NA | NA | 0.83 |
| Executive functioning | 0.0025 (-0.0572, 0.0623) | 0.0089 (-0.0484, 0.0661) | NA | NA | 0.86 |
| Verbal memory & learning | -0.0038 (-0.1009, 0.0933) | 0.0064 (-0.0907, 0.1034) | NA | NA | 0.96 |
| Visual memory | 0.0165 (-0.0532, 0.0862) | 0.0241 (-0.0431, 0.0913) | NA | NA | 0.23 |
| White subjects only, N = 517 | |||||
| Language | -0.0724 (-0.1371, -0.0077) | -0.0241 (-0.0764, 0.0281) | NA | NA | 0.33 |
| Processing speed | -0.0394 (-0.129, 0.0502) | -0.0241 (-0.1162, 0.068) | NA | NA | 0.83 |
| Eye-hand coordination | -0.0876 (-0.1449, -0.0304) | -0.0635 (-0.1183, -0.0087) | NA | NA | 0.071 |
| Executive functioning | -0.0927 (-0.1475, -0.0379) | -0.0635 (-0.1158, -0.0112) | NA | NA | 0.053 |
| Verbal memory & learning | -0.1054 (-0.1851, -0.0258) | -0.0762 (-0.1534, 0.001) | NA | NA | 0.034 |
| Visual memory | -0.094 (-0.1811, -0.0069) | -0.0648 (-0.1544, 0.0248) | NA | NA | 0.31 |
1
Bivariate Wald tests for the null hypothesis that both linear and spline lead coefficients equal 0, with chi-square reference distribution.
2
12.7 μg/g is the IQR of tibia lead among individuals with non-negative concentrations (n=965)
3
The Base Model adjusted for age, sex and interviewer. All subsequent models included these as adjustments.