TABLE 2

Comparison of Characteristics of Children 8 to 15 Years of Age Not Included and Included in Study Sample

Not IncludedIncluded
Male, n (%)a2247 (51.2) (N = 4578)570 (53.2) (N = 1139)
Race/ethnicity, n (%)a
    Non-Hispanic white1138 (59.6) (N = 4578)325 (63.3) (N = 1139)
    Black1533 (16.0) (N = 4578)342 (13.2) (N = 1139)
    Mexican American1555 (11.7) (N = 4578)382 (11.6) (N = 1139)
    Other/multiracial352 (12.7) (N = 4578)90 (12.0) (N = 1139)
PIR, n (%)a
    <1.01390 (23.4) (N = 4145)363 (21.4) (N = 1139)
    1.0–1.841009 (20.7) (N = 4145)274 (21.3) (N = 1139)
    1.85–3.0730 (20.6) (N = 4145)214 (21.6) (N = 1139)
    >3.01016 (35.3) (N = 4145)288 (35.8) (N = 1139)
Maternal smoking during pregnancy, n (%)a697 (19.8) (N = 4509)152 (17.7) (N = 1125)
ADHD, n (%)a
    Any subtype295 (12.2) (N = 2859)119 (12.1) (N = 1139)
    Inattentive subtype133 (5.9) (N = 2865)69 (7.6) (N = 1139)
    Hyperactive subtype81 (3.2) (N = 2860)21 (1.5) (N = 1139)
    Combined subtype81 (3.1) (N = 2865)29 (3.0) (N = 1139)
Age, weighted mean ± SE, mo144 ± 0.6 (N = 4578)143 ± 1.0 (N = 1139)
BMI, weighted mean ± SE, kg/m220.8 ± 0.1 (N = 4502)20.6 ± 0.2 (N = 1139)
Blood lead level, weighted mean ± SE, μg/dL1.4 ± 0.04 (N = 4036)1.4 ± 0.04 (N = 1093)
Maternal age at birth, weighted mean ± SE, y26.3 ± 0.2 (N = 4432)26.4 ± 0.3 (N = 1107)
  • a Proportions were weighted.