Table 2.
Characteristics of NHANES participants 60+ years and older sub-sampled for blood metals, by continuous variable measures, NHANES 1999-2002 and 2011-2014
| Composite Cognitive Z-Score Analysis Sample (NHANES 2011-2014)a |
DSST Z-Score Analysis Sample (NHANES 1999-2002 and 2011-2014)b |
|||
|---|---|---|---|---|
| Meanc | SEc | Meanc | SEc | |
| Age | 69.7 | 0.30 | 70.4 | 0.21 |
| Blood lead (μg/dL) | 1.83 | 0.08 | 2.19 | 0.06 |
| Patella lead (μg Pb / g bone) | 36.6 | 0.41 | 38.2 | 0.29 |
| CERAD immediate recall | ||||
| Raw score | 7.7 | 0.09 | - | - |
| Z-scored | 0.21 | 0.05 | - | - |
| CERAD delayed recall | ||||
| Raw score | 6.1 | 0.09 | - | - |
| Z-scored | 0.18 | 0.04 | - | - |
| Animal Fluency | ||||
| Raw score | 18.1 | 0.22 | - | - |
| Z-scored | 0.36 | 0.04 | - | - |
| DSST | ||||
| Raw score | 52.1 | 0.68 | 49.8 | 0.53 |
| Z-scored | 0.47 | 0.04 | 0.46 | 0.03 |
| Composite z-scored | 0.39 | 0.04 | - | - |
NHANES National Health and Nutrition Examination Survey
DSST Digit Symbol Substitution Test
a
Composite Cognitive z-score sample: unweighted N=1,700; weighted N = 50,835,920
b
DSST z-score sample: unweighted N=3,924; weighted N = 44,366,505
c
Means and SEs weighted for NHANES survey weighting
d
Standardized score, mean of 0 and standard deviation of 1