TABLE 4

Multivariate Linear Regression Models Testing Main and Interactive Effects of Prenatal Chlorpyrifos Exposure on 12-, 24-, and 36-Month MDI Scores, Adjusted for Race, Gender, Maternal Education, Maternal IQ, Gestational Age, and Prenatal ETS Exposure

VariableModel 1: 12 mo (n = 229)Model 2: 24 mo (n = 225)Model 3: 36 mo (n = 228)
B, Mean ± SEPB, Mean ± SEPB, Mean ± SEP
Constant103.893 ± 27.49<.00110.709 ± 34.37NS52.724 ± 28.29.064
Prenatal chemical exposures
    ETSa0.456 ± 1.39.744−3.032 ± 1.66.069−0.058 ± 1.44.968
    Chlorpyrifosb−0.344 ± 1.66.836−1.480 ± 2.03.466−3.327 ± 1.76.060
Covariates
    Race/ethnicityc0.229 ± 1.44.8746.176 ± 1.73<.0016.286 ± 1.47<.001
    Genderd−2.974 ± 1.30.023−3.760 ± 1.58.018−3.680 ± 1.34.006
    Gestational age0.355 ± 0.44.4211.466 ± 0.59.0131.287 ± 0.47.007
    Maternal IQe−5.982 ± 4.96.2291.715 ± 5.66.762−6.751 ± 4.89.169
    Low maternal educationf−0.278 ± 1.41.843−2.298 ± 1.70.179−2.888 ± 1.45.048
    HOME score0.173 ± 0.12.1500.200 ± 0.14.1650.589 ± 0.13<.001
R20.0400.1460.251
  • The sample included all children who had reached 3 years of age with data from the prenatal maternal interview, biomarkers of exposure, and complete data on all covariates. Sample sizes for age-specific models ranged from 225 to 229 because of missed and/or unscorable assessments (<50). B indicates unstandardized regression coefficient; NS, not significant.

  • a Prenatally exposed = 1; not exposed = 0.

  • b High exposure (>6.17 pg/g) = 1; low exposure (≤6.17 pg/g) = 0.

  • c Black = 2; Dominican = 1.

  • d Male = 2; female = 1.

  • e Measured with the Test of Nonverbal Intelligence, Second Edition,42 natural logarithmically transformed.

  • f No high school degree = 1; high school degree = 0.