Table 3

Random effects model showing relationship between smoking and smoking cessation and CBCL z-scores at each age

Random effects model: years 2 to 14 inclusive
Estimate of effects (EE)
95% CI
Significance (p-value)
Unadjusted analysisAdjusted analysis**
Predictor variablesTotal behaviourInternalising behaviourExternalising behaviourTotal behaviourInternalising behaviourExternalising behaviour
Smoking in pregnancy‡
1–10 cigarettes daily pre-pregnancy§−0.03
−0.13, 0.06
0.493		−0.02
−0.11, 0.07
0.647		−0.02
−0.12, 0.07
0.654		−0.11*
−0.21, −0.01
0.032		−0.07
−0.17, 0.02
0.129		−0.09
−0.19, 0.01
0.076
11+ cigarettes daily pre-pregnancy§0.05
−0.05, 0.15
0.305		0.00
−0.09, 0.09
0.974		0.09
−0.00, 0.19
0.061		−0.02
−0.13, 0.09
0.705		−0.04
−0.14, 0.06
0.407		0.02
−0.09, 0.12
0.749
Smoked before and during pregnancy0.38†
0.30, 0.47
<0.001		0.27†
0.19, 0.35
<0.001		0.41†
0.33, 0.49
<0.001		0.16†
0.06, 0.26
0.002		0.10*
0.00, 0.19
0.049		0.21†
0.10, 0.31
<0.001

  • ↵* p<0.05.

  • ↵† p<0.005.

  • ↵‡ Reference category never smoked.

  • ↵§ No longer smoking by 18 weeks gestation.

  • ↵ Adjusted for child's age as a random slope.

  • ↵** Adjusted for maternal age at conception, maternal education at 18 weeks gestation, the presence of the biological father in the family home at 18 weeks gestation, family income at 18 weeks gestation, total stress events in pregnancy, alcohol intake at 18 weeks gestation, birth weight (grams), gestational age (weeks), breast feeding duration (months), family functioning from 5 to 14 years and child's age as a random slope.

  • CBCL, Child Behaviour Checklist.