Table 3.
Association of log10-transformed infant salivary cotinine (ng/ ml) with Strengths and Difficulties Questionnaire (SDQ) scores in Chinese preschoolers.
| Mean (SD)SDQ score | Coefficient (95% confidence interval)a | |||
|---|---|---|---|---|
| Crude | Model 1b | Model 2c | ||
| Imputed data analyses (n = 301) | ||||
| Emotional symptoms | 1.1 (1.5) | 0.11 (−0.44, 0.66) | 0.05 (−0.57, 0.66) | −0.00 (−0.62, 0.62) |
| Conduct problems | 2.2 (1.5) | 0.91 (0.14, 1.67) | 0.93 (0.07, 1.78) | 0.90 (0.03, 1.76) |
| Hyperactivity/inattention | 3.8 (2.3) | 1.19 (0.25, 2.13) | 1.27 (0.22, 2.32) | 1.12 (0.07, 2.17) |
| Peer relationship problems | 2.4 (1.3) | 0.12 (−0.38, 0.61) | 0.04 (−0.52, 0.60) | −0.03 (−0.58, 0.51) |
| Prosocial behaviour | 5.6 (2.8) | −0.24 (−1.30, 0.81) | −0.14 (−1.30, 1.02) | −0.10 (−1.28, 1.09) |
| Total difficulties | 9.5 (5.4) | 2.33 (0.19, 4.46) | 2.31 (−0.07, 4.70) | 1.99 (−0.37, 4.35) |
| Complete case analyses (n = 189) | ||||
| Emotional symptoms | 1.1 (1.4) | 0.21 (−0.33, 0.75) | 0.13 (−0.44, 0.70) | 0.05 (−0.52, 0.62) |
| Conduct problems | 2.1 (2.0) | 0.68 (−0.06, 1.41) | 0.68 (−0.11, 1.47) | 0.76 (−0.02, 1.54) |
| Hyperactivity/inattention | 3.8 (2.3) | 1.08 (0.14, 2.01) | 1.18 (0.20, 2.16) | 1.02 (0.06, 1.99) |
| Peer relationship problems | 2.5 (1.3) | 0.14 (−0.40, 0.68) | −0.00 (−0.55, 0.56) | −0.00 (−0.57, 0.57) |
| Prosocial behaviour | 5.5 (2.7) | −0.07 (−1.07, 0.94) | 0.03 (−1.05, 1.11) | −0.07 (−1.18, 1.03) |
| Total difficulties | 9.3 (5.1) | 2.05 (−0.07, 4.17) | 1.93 (−0.25, 4.12) | 1.69 (−0.48, 3.86) |
aBold face indicates P < 0.05. bAdjusted for child age, sex, birthweight, monthly household income, housing type, maternal education level. cModel 1 additionally adjusted for maternal depressive symptoms assessed by Patient Health lgQuestionnaire-9.