TABLE 2

AORs for ADHD According to Environmental Exposure, Sociodemographic Characteristics, and Medical Factors (N = 2588)

CharacteristicAOR (95% CI)P
Blood lead level
    First tertile (0.2–0.8 μg/dL) (reference)1.0
    Second tertile (0.9–1.3 μg/dL)1.7 (0.97–2.9).06
    Third tertile (>1.3 μg/dL)2.3 (1.5–3.8).001
Prenatal tobacco exposure
    Yes2.4 (1.5–3.7).001
    No (reference)1.0
Household smoke exposurea
    First tertile (0.2–0.027 ng/mL) (reference)1.0
    Second tertile (0.028–0.202 ng/mL)0.9 (0.4–1.7).70
    Third tertile (0.203–10 ng/mL)0.8 (0.4–1.7).58
Gender
    Male1.9 (1.4–2.5)<.001
    Female (reference)1.0
Age
    8–11 y1.1 (0.8–1.6).60
    12–15 y (reference)1.0
Race/ethnicity
    Mexican American0.5 (0.3–0.9).03
    Non-Hispanic black0.5 (0.3–0.9).02
    Other race/ethnicity0.4 (0.2–1.1).08
    Non-Hispanic white (reference)1.0
Income/poverty ratio
    First quintile (0–0.93)1.9 (0.9–4.1).09
    Second quintile (0.94–1.70)1.5 (0.7–3.4).31
    Third quintile (1.71–2.75)1.5 (0.8–3.1).23
    Fourth quintile (2.76–4.24)1.4 (0.7–2.6).35
    Fifth quintile (>4.24) (reference)1.0
Attended preschool
    Yes1.6 (1.1–2.1).01
    No (reference)1.0
Mother's age at child's birth
    ≤18 y1.9 (0.96–3.6).06
    >18 y (reference)1.0
Birth weight
    <2.5 kg1.5 (0.7–2.9).25
    ≥2.5 kg (reference)1.0
  • Subjects with ADHD met DSM-IV criteria for any ADHD subtype.

  • a Assessed through serum cotinine levels.