Table 1.
Comparison of the Lead Safe Homes Study cohort and control group BLL values at the two year time point (from 18 to 30 months).
| Characteristic | LSH Group | Control Group | P-Value |
|---|---|---|---|
| Maximum N | 314 | 628 | |
| N (%) with recorded BLL value | 159 (50.6%) | 331(52.7%) | >0.5 a |
| BLL is venous specimen N (%) | 151/158 (95.6%) | 304/331 (91.8%) | 0.1 a |
| Mean age at draw (months) ± SD | 23.8 ± 3.4 | 23.6 ± 3.1 | 0.6 b |
| Median age at draw (months) | 24.1 | 24.2 | |
| Age range (months) | 18–30 | 18–30 | |
| Median blood lead (μg/dL) | 3.2 | 3.3 | |
| GM BLL, μg/dL (95% CI) | 3.7 (3.4, 4.0) | 3.5 (3.3, 3.7) | 0.4 b |
| Range of BLLs (μg/dL) | (0.8–39.4) | (0.7–33.1) | |
| Percentages at different BLL levels | |||
| ≥5 µg/dL | 47/159 (29.6%) | 82/331 (24.8%) | 0.3 a |
| ≥10 µg/dL | 8/159 (5.0%) | 22/331 (6.6%) | 0.5 a |
| ≥20 µg/dL | 1/159 (0.6%) | 4/331 (1.2%) | 0.9 c |
BLLs = blood lead levels; CI = confidence interval; GM = geometric mean; LSH = Lead Safe Homes; SD = standard deviation; a P-values are two-tailed significance for uncorrected chi-square; b P-values are two-tailed significance for unpaired t test; c P-values are two-tailed significance for continuity corrected chi-square.