Table 1.
Adjusted Regression Coefficients for Cord-Mercury Concentration as a Predictor of 8-Year Psychometric Outcomes in the New and Combined Subgroups, Avon Longitudinal Study of Parents and Children, United Kingdom, 1991–2000
| WISC-III Score | Model 1a | Model 2b | Model 3c | ||||||
|---|---|---|---|---|---|---|---|---|---|
| No. | βd | 95% CId | No. | βd | 95% CId | No. | βd | 95% CId | |
| Extended sample (new group) | 1,051 | 795 | 792 | ||||||
| Total IQ | 11.6 | 6.6, 16.4 | 3.5 | −2.0, 9.0 | 2.6 | −3.4, 8.6 | |||
| Verbal IQ | 12.8 | 7.9, 17.8 | 3.2 | −2.3, 8.8 | 1.9 | −4.1, 7.9 | |||
| Performance IQ | 7.2 | 2.1, 12.3 | 2.8 | −3.3, 8.8 | 2.6 | −4.0, 9.1 | |||
| Joint sample (pilot group + new group) | 2,281 | 1,813 | 1,808 | ||||||
| Total IQ | 12.1 | 8.9, 15.2 | 3.0 | −0.4, 6.4 | 2.6 | −1.1, 6.4 | |||
| Verbal IQ | 13.3 | 10.1, 16.6 | 3.4 | −0.1, 6.9 | 2.9 | −0.9, 6.8 | |||
| Performance IQ | 7.5 | 4.2, 10.8 | 1.8 | −2.0, 5.5 | 1.6 | −2.5, 5.7 | |||
| Joint sample complete cases | 1,808 | 1,808 | 1,808 | ||||||
| Total IQ | 12.1 | 8.6, 15.6 | 3.0 | −0.4, 6.5 | 2.6 | −1.1, 6.4 | |||
| Verbal IQ | 12.9 | 9.2, 16.5 | 3.3 | −0.2, 6.8 | 2.9 | −0.9, 6.8 | |||
| Performance IQ | 8.0 | 4.3, 11.8 | 1.8 | −1.9, 5.6 | 1.6 | −2.6, 5.7 | |||
Abbreviations: CI, confidence interval; IQ, intelligence quotient; WISC-III, Wechsler Intelligence Scale for Children, Third Edition.
a Adjusted for sex, age, and examiner. These analyses included subjects without genetic data, resulting in a slightly larger sample size than the genetic data analyses.
b Additionally adjusted for parental education level, maternal age, smoking during pregnancy, social class, parity, and house ownership status.
c Additionally adjusted for maternal estimated omega-3 intake (omega-3 intake estimated from seafood intake).
d β and 95% CI for log10(cord-mercury (ng/g)).