TABLE 1

Sample Characteristics in the ALSPAC and Generation R Cohorts

CharacteristicnMedianInterquartile RangeCategoryn%
Child characteristics
    ALSPAC
        Child nonverbal score (DANVA)322143–6
        Child sentence length (MacArthur)46582421–26
        Child word production (MacArthur)4712241229–246
        Child behavioral problems (SDQ)
            Total487385–11
            Hyperactivity487342–5
            Emotional487310–2
            Conduct problems487321–3
    Generation R
        Child nonverbal score (PARCA)318747.543.8–51.0
        Child sentence length (LDS)23984.62.6–6.2
        Child word production (LDS)2385259222–283
        Child behavioral problems (CBCL)
        Total problems2046169–26
        Attention problems248310–2
        Internalizing204631–6
        Externalizing204573–12
Parental characteristics
    ALSPAC
        Maternal overweight/obesity4886Yes104021.3
No384678.7
        Paternal overweight/obesity4886Yes230047.1
No258652.9
        Maternal educationa4886CSE/none57311.7
Vocational4018.2
O level174635.7
A level128326.3
Degree88318.1
        Paternal educationa4886CSE/none79616.3
Vocational3737.6
O level110222.6
A level145129.7
Degree116423.8
        Family weekly income (net)4886<£1002044.2
£100–19957611.8
£200–299128626.3
£300–399118524.3
>£400163533.5
        Family social classb4886IV/V1743.6
IIIM4539.3
IIINM119524.5
II222145.5
I84317.3
        Maternal prenatal smoking4886Yes85017.4
No403682.6
        Breastfeeding4792Yes68914.4
No410385.6
    Generation R
        Maternal overweight/obesity3187Yes70422.1
No248377.9
        Paternal overweight/obesity3187Yes154348.4
No164451.6
        Maternal educationc3187Primary/none1284.0
Secondary 12879.0
Secondary 285626.9
Higher 181425.5
Higher 2110234.6
        Paternal educationc3187Primary/none1765.5
Secondary 137411.7
Secondary 278924.8
Higher 165320.5
Higher 2119537.5
        Family monthly income (net)3187€900 or less1494.7
€900–14002307.2
€1400–18002116.6
€1800–220034910.9
>€2200224870.5
        Maternal prenatal smoking (any)3187Yes70422.1
No248377.9
        Breastfeeding2967Yes205469.2
No91330.8
  • DANVA indicates Diagnostic Analysis of Nonverbal Accuracy test; LDS, Language Development Survey; CSE, Certificate of Secondary Education.

  • a O level, national school exams at 16 years; A level, national school exams at 18 years.

  • b IV/V, partly skilled occupations/unskilled occupations; IIIM, manual, skilled occupations; IIINM, nonmanual, skilled occupations; II, managerial and technical occupations; I, professional occupations.

  • c Secondary 1, lower vocational, intermediate general school, or 3 years general secondary school; Secondary 2, >3 years general school, secondary school, intermediate vocational, or first year higher vocational; Higher 1, higher vocational or bachelor's degree; Higher 2, higher academic education or PhD.