Table 3

 Pediculosis during childhood and risk of childhood acute leukaemia

Cases (n = 280)Controls (n = 288)OR*95% CI
*Odds ratios adjusted for age, gender, hospital, ethnic origin, and maternal educational level.
‡Two children received preventive treatment without having pediculosis.
Pediculosis
    Never1801951.0Reference
    Ever98901.6(1.0–2.6)
    Missing23
    Once51481.5(0.9–2.5)
    Twice or more47421.9(1.1–3.3)
Pediculosis treatments
    No treatment†1791941.0Reference
    Insecticidal shampoo70601.9(1.1–3.2)
    Other (vinegar, sweet almond oil)130.3(0.03–2.9)
    Missing3031
    Pyrethroid65552.0(1.1–3.4)
    Pyrethroid only59462.2(1.2–3.8)
    Lindane (organochlorine)642.1(0.5–8.7)
    Malathion (organophosphorus)5100.7(0.2–2.4)