Table 1

Prevalence of low birth weight, small-for-gestational-age, small HC, preterm birth, ADHD and attention problems in the ALSPAC and Pelotas cohorts

VariableALSPAC n (%)
(N=6768)
Pelotas n (%)
(N=3508)
χ2
Exposures
 Low birth weight238 (3.5)274 (7.8)89.99**
 SGA512 (7.6)496 (14.2)113.19**
 Small HC264 (4.8)470 (13.4)211.02**
 Preterm birth302 (4.4)445 (12.7)237.77**
Outcomes
 DAWBA
  Hyperactive-impulsive ADHD20 (0.3)13 (0.4)0.45
  Inattentive ADHD54 (0.8)11 (0.3)8.39*
  Combined ADHD68 (1.0)56 (1.6)7.13*
  Any ADHD disorder142 (2.1)92 (2.6)3.16
 SDQ
  Attention difficulties†719 (10.5)480 (13.7)22.94**
  • *p<0.05; **p<0.001.

  • †SDQ score ≥7.

  • ADHD, attention deficit hyperactivity disorder; ALSPAC, Avon Longitudinal Study of Parents and Children; DAWBA, Development and Well-Being Assessment; HC, head circumference; SDQ, Strengths and Difficulties Questionnaire; SGA, small-for-gestational age.