Table 1.

Distribution of 131 cases of ALL ages 1 to 4 years and 131 age- and gender-matched controls by gender, age, maternal age at birth, birth weight, maternal smoking during pregnancy, maternal years of schooling, and maternal occupation

VariablesCases, n (%)Controls, n (%)P
Gender
    Male75 (57.3)75 (57.3)Matched variable
    Female56 (42.7)56 (42.7)
Age (y)
    126 (19.8)22 (16.8)Matched variable
    242 (32.1)41 (31.3)
    339 (29.8)44 (33.6)
    424 (18.3)24 (18.3)
Maternal age at the time of delivery (y)
    <2320 (15.2)24 (18.3)0.08*
    23-2523 (17.6)24 (18.3)
    26-2818 (13.8)25 (19.1)
    29-3121 (16.0)27 (20.6)
    32-3427 (20.6)17 (13.0)
    ≥3522 (16.8)14 (10.7)
Birth weight (g)
    <3,00033 (25.2)22 (16.8)0.48*
    3,000-3,49948 (36.6)58 (44.3)
    3,500-3,99939 (29.8)42 (32.0)
    ≥4,00011 (8.4)9 (6.9)
Maternal smoking during pregnancy
    No101 (77.1)115 (87.8)0.02
    Yes30 (22.9)16 (12.2)
Maternal years of schooling
    <1241 (31.3)32 (24.4)0.49*
    1258 (44.3)68 (51.9)
    ≥1332 (24.4)31 (21.7)
Mother employed
    No61 (46.6)59 (45.0)0.80
    Yes70 (53.4)72 (55.0)
  • * P from χ2 for trend (1 df).