Regression analysis of the effect of blood lead levels on behaviour, attention, co-ordination and school performance outcomes, adjusted for eight confounders
| Linear log lead concentration | Categorical: 2–5 μg/dl | Categorical: 5–10 μg/dl | Categorical: >10 μg/dl | |||||
| OR (95% CI) | p Value | OR (95% CI) | p Value | OR (95% CI) | p Value | OR (95% CI) | p Value | |
| SDQ | ||||||||
| Teacher- hyperactivity | 1.41 (0.95 to 2.08) | 0.09 | 0.84 (0.47 to 1.52) | 0.566 | 1.25 (0.67 to 2.33) | 0.486 | 2.82 (1.08 to 7.35) | 0.034 |
| Teacher- total difficulties | 1.29 (0.87 to 1.90) | 0.20 | 1.02 (0.58 to 1.79) | 0.957 | 1.30 (0.71 to 2.37) | 0.394 | 2.69 (1.06 to 6.81) | 0.037 |
| Parent- hyperactivity | 1.20 (0.91 to 1.58) | 0.19 | 0.88 (0.57 to 1.34) | 0.540 | 1.24 (0.79 to 1.97) | 0.350 | 1.30 (0.62 to 2.71) | 0.484 |
| Parent- total difficulties | 1.13 (0.85 to 1.48) | 0.40 | 1.13 (0.74 to 1.72) | 0.569 | 1.27 (0.81 to 2.01) | 0.299 | 1.20 (0.57 to 2.51) | 0.636 |
| DAWBA | ||||||||
| Activity score | 1.11 (0.83 to 1.48) | 0.48 | 0.81 (0.50 to 1.29) | 0.369 | 1.24 (0.77 to 2.01) | 0.369 | 0.96 (0.44 to 2.10) | 0.912 |
| Attention score | 1.13 (0.84 to 1.51) | 0.42 | 0.83 (0.52 to 1.32) | 0.427 | 1.28 (0.79 to 2.06) | 0.323 | 1.15 (0.54 to 2.47) | 0.713 |
| Behaviour | ||||||||
| Anti-social activities | 1.54 (1.01 to 2.33) | 0.04 | 0.93 (0.47 to 1.83) | 0.833 | 1.44 (0.73 to 2.84) | 0.289 | 2.90 (1.05 to 8.03) | 0.040 |
| Attention | ||||||||
| Selective attention | 1.01 (0.76 to 1.34) | 0.94 | 1.03 (0.66 to 1.61) | 0.907 | 0.99 (0.62 to 1.57) | 0.958 | 1.14 (0.54 to 2.40) | 0.723 |
| Dual attention | 0.92 (0.66 to 1.31) | 0.66 | 1.13 (0.66 to 1.91) | 0.662 | 1.22 (0.70 to 2.14) | 0.489 | 0.48 (0.20 to 1.13) | 0.094 |
| Same worlds | 1.26 (0.94 to 1.68) | 0.12 | 0.99 (0.64 to 1.53) | 0.947 | 1.31 (0.82 to 2.08) | 0.262 | 1.48 (0.69 to 3.15) | 0.311 |
| Opposite worlds | 1.18 (0.88 to 1.57) | 0.26 | 1.29 (0.83 to 2.01) | 0.249 | 1.26 (0.79 to 2.03) | 0.334 | 1.04 (0.49 to 2.21) | 0.918 |
| SATs | ||||||||
| Reading | 0.64 (0.47 to 0.86) | 0.004 | 0.88 (0.54 to 1.43) | 0.608 | 0.51 (0.32 to 0.82) | 0.006 | 0.62 (0.28 to 1.35) | 0.226 |
| Writing | 0.61 (0.46 to 0.82) | 0.001 | 1.08 (0.69 to 1.71) | 0.729 | 0.49 (0.31 to 0.78) | 0.003 | 0.44 (0.21 to 0.93) | 0.031 |
| Spelling | 0.55 (0.36 to 0.83) | 0.004 | 1.41 (0.78 to 2.53) | 0.252 | 0.76 (0.40 to 1.42) | 0.383 | ||
| Mathematics | 0.75 (0.56 to 1.00) | 0.053 | 1.38 (0.86 to 2.20) | 0.177 | 0.73 (0.46 to 1.15) | 0.171 | 0.86 (0.41 to 1.81) | 0.694 |
DAWBA, Development And Well-being Assessment; SATs, Standard Assessment Tests; SDQ, Strengths and Difficulties Questionnaire. Reference group 0–2 μg/dl.