Table 1

 Distribution of child- and family-related potential confounding factors according to the presence of learning disability or attention deficit disorder

Learning disabilityAttention deficit disorder
No (n = 234)Yes (n = 44)p ValueNo (n = 251)Yes (n = 26)P Value
Values are given as mean (SD) or percentage.
Children’s variables
    Age (years)13.4 (1.0)13.2 (1.1)0.1913.4 (1.1)13.0 (1.0)0.06
    Male (%)48.763.60.0750.257.70.47
    White (%)17.543.2<0.0118.353.8<0.01
    Birth weight (g)3288 (682)3151 (709)0.233293 (660)3049 (879)0.18
    Body mass index23.1 (5.4)22.3 (4.5)0.3722.9 (5.1)23.3 (6.9)0.79
    Saturated fat intake (g)27.5 (14.7)26.9 (17.1)0.8127.0 (15.1)31.4 (14.5)0.16
    Blood lead (μg/dl)1.6 (1.3)1.6 (0.9)0.791.6 (1.2)1.8 (1.4)0.41
    Blood cadmium (μg/l)0.3 (0.1)0.3 (0.2)0.670.3 (0.2)0.3 (0.2)0.86
Family and maternal variables
    Poverty:income ratio1.8 (1.3)1.7 (1.5)0.661.8 (1.4)1.4 (1.4)0.22
    Mother’s age at pregnancy (years)25.0 (6.1)23.6 (5.7)0.1725.1 (6.1)21.9 (4.6)0.01
    Cigarette smoking during pregnancy (%)15.040.9<0.0116.742.30.02