TABLE 1.

Univariate Relationship Between Maternal Smoking During Pregnancy in Singleton Deliveries and Hyperkinetic Disorder in the Offspring, Presented as RRs with 95% CIs From a Conditional Logistic Regression Model

NnUnadjusted RR (95% CI)*
Smoking
    Nonsmoker2576691
    Smoker13591012.9 (2.1–4.0)
Perinatal data
    Apgar score at 5 min
        ≥738671651
        <74852.6 (1.0–6.6)
    Birth weight, g
        ≥250037891531
        <2500146173.1 (1.8–5.3)
    Gestational age, wk
        ≥3737291461
        <37158183.1 (1.8–5.2)
Maternal age, y
    <2010441.0 (0.3–2.8
    20–24746511.8 (1.2–2.6)
    25–291628631
    30–341089421.0 (0.6–1.4)
    ≥35368100.7 (0.3–1.3)
Paternal age, y§
    ≤4538001591
    >457141.3 (0.5–3.7)
  • Hyperkinetic offspring n = 170 (F90.0 [n = 102]; F90.1 [n = 33]; F90.8 [n = 2]; F90.9 [n = 33]) and 3765 control subjects.

  • * Cases and control subjects are matched for age, gender, and calendar time.

  • Missing information for 20.

  • Missing information for 49.

  • § Missing information for 64.