TABLE 4

Linear Regression of CSBS Total Score and CDI Vocabulary Production at 24 Months

VariableCSBS (N = 1562)CDI (N = 1570)
Coefficient95% CIPCoefficient95% CIP
Female gendera3.21.8 to 4.7<.00153.037.4 to 68.6<.001
Twin birtha−2.3−7.1 to 2.6.36−45.9−97.7 to 5.9.08
Preterm birth (<36 wk)a−3.3−8.0 to 1.4.1719.2−31.3 to 69.7.46
Birth weight, kgb−0.8−2.4 to 0.8.317.2−9.4 to 23.8.40
Birth order (first child reference)c.70.02
    Second child1.1−0.5 to 2.7−9.7−27.3 to 7.9
    Third child0.6−1.8 to 3.0−41.3−67.0 to −15.5
    Fourth child0.8−4.5 to 6.0−38.0−94.7 to 18.7
    Fifth child or more4.4−7.21 to 16.046.8−78.3 to 172.0
Non-English-speaking backgrounda−0.8−4.31 to 2.7.65−75.4−116.3 to −34.5<.001
SEIFA disadvantage (1st quintile reference)c.66.31
    2nd quintile1.0−2.6 to 4.6−19.3−58.0 to 19.5
    3rd quintile−0.4−3.3 to 2.5−9.3−41.2 to 22.6
    4th quintile−0.7−3.6 to 2.1−26.4−57.6 to 4.7
    5th quintile (least disadvantaged)0.4−2.7 to 3.6−13.4−47.2 to 20.5
Family history of speech/language difficultiesa−2.5−4.2 to −0.8.004−45.8−63.9 to −27.7<.001
Maternal mental health problema−1.2−2.8 to 0.3.121.1−15.6 to 17.8.90
Maternal vocabulary scoreb0.30.1 to 0.5<.0011.6−0.2 to 3.4.08
Maternal education level (≤12 y reference)c.12.66
    13 y1.1−0.9 to 3.08.4−12.6 to 29.3
    University degree1.8−0.5 to 4.015.5−8.5 to 39.5
    Postgraduate degree3.10.5 to 5.68.1−19.6 to 35.7
Maternal age at birth of child, yb−0.3−0.5 to −0.2<.001−0.6−2.6 to 1.3.53
  • a Binary predictor: regression coefficient represents the mean difference in outcome score between the 2 categories.

  • b Quantitative predictor: regression coefficient represents the mean increase in outcome score for each unit increase in the predictor.

  • c Categorical predictor: regression coefficient represents the mean difference in outcome score between the category of interest and the reference category.