Table 1 Descriptive statistics for child ADHD scores (age 8 years) and sample demographic characteristics.
N | Mean (SD) | Median | Range | ||
|---|---|---|---|---|---|
ADHD total score | Female | 4570 | 25.25 (6.43) | 24 | 18–70 |
Male | 4884 | 27.75 (7.96) | 26 | 18–72 | |
Inattention subscale | Female | 4570 | 13.23 (3.68) | 12 | 9–36 |
Male | 4884 | 14.65 (4.47) | 14 | 9–36 | |
Hyperactivity-impulsivity subscale | Female | 4570 | 12.01 (3.52) | 11 | 9–36 |
Male | 4884 | 13.10 (4.32) | 12 | 9–36 | |
Parental age at baseline | Mothers | 19,506 | 30.08 (4.46) | 30 | 17–47 |
Fathers | 19,506 | 32.51 (5.15) | 32 | 18–61 | |
Mothers | Fathers | ||||
n (%) | n (%) | ||||
Highest qualification | Lower secondary school | 378 (2.07) | 675 (3.84) | ||
Upper secondary school, basic | 795 (4.36) | 906 (5.15) | |||
Vocational upper secondary school | 2280 (12.51) | 4469 (25.42) | |||
Upper secondary school, completed | 2593 (14.23) | 2158 (12.27) | |||
Higher education, undergraduate level | 7761 (42.59) | 5087 (28.93) | |||
Higher education, graduate level | 4414 (24.22) | 4286 (24.38) | |||
Household income | No income | 318 (1.71) | 108 (0.6) | ||
<150,000 NOK | 2629 (14.12) | 919 (5.07) | |||
151,000–199,999 NOK | 1922 (10.32) | 673 (3.72) | |||
200,000–299,999 NOK | 6369 (34.35) | 3795 (20.95) | |||
300,000–399,999 NOK | 5033 (27.03) | 6264 (34.58) | |||
400,000–499,999 NOK | 1457 (7.83) | 3277 (18.09) | |||
> 500,000 NOK | 863 (4.64) | 3076 (16.98) | |||
