TABLE 6

Linear Regression Analysis of the 3 CSBS Composite Scores at 24 Months (N = 1562)

VariableSocialSpeechSymbolic
Coefficient95% CIPCoefficient95% CIPCoefficient95% CIP
Female gendera0.32−0.06 to 0.70.101.000.58 to 1.42<.0011.160.78 to 1.55<.001
Twin birtha−0.55−1.81 to 0.71.39−0.44−1.83 to 0.95.54−0.43−1.70 to 0.85.51
Preterm birth (<36 wk)a−1.14−2.37 to 0.09.07−0.13−1.49 to 1.22.85−0.31−1.56 to 0.93.62
Birth weight, kgb−0.41−0.82 to 0.00.050.25−0.20 to 0.70.280.26−0.15 to 0.68.21
Birth order (first child reference)c.04.24.71
    Second child0.510.08 to 0.94−0.24−0.71 to 0.24−0.03−0.47 to 0.40
    Third child0.890.26 to 1.52−0.75−1.44 to −0.06−0.43−1.06 to 0.20
    Fourth child0.79−0.58 to 2.17−0.24−1.76 to 1.27−0.26−1.65 to 1.13
    Fifth child or more0.51−2.54 to 3.551.40−1.96 to 4.750.54−2.54 to 3.62
Non-English-speaking backgrounda0.15−0.77 to 1.07.75−0.41−1.43 to 0.60.42−0.82−1.75 to 0.10.08
SEIFA disadvantage (1st quintile reference)c.47.52.41
    2nd quintile0.22−0.72 to 1.16−0.51−1.55 to 0.520.33−0.62 to 1.28
    3rd quintile−0.18−0.94 to 0.59−0.51−1.35 to 0.340.06−0.72 to 0.84
    4th quintile−0.42−1.17 to 0.34−0.62−1.45 to 0.210.50−0.26 to 1.27
    5th quintile (least disadvantaged)−0.22−1.04 to 0.60−0.25−1.15 to 0.660.26−0.57 to 1.09
Family history of speech/language difficultiesa−0.07−0.51 to 0.37.76−0.92−1.41 to −0.44<.001−0.96−1.41 to −0.51<.001
Maternal mental health problema−0.32−0.73 to 0.08.12−0.04−0.49 to 0.40.85−0.54−0.95 to −0.13.01
Maternal vocabulary scoreb0.050.01 to 0.09.030.100.05 to 0.15<.0010.060.02 to 0.11.007
Maternal education level (≤12 y reference)c.86<.001.005
    13 y0.13−0.39 to 0.640.51−0.06 to 1.070.37−0.15 to 0.89
    University degree−0.03−0.62 to 0.551.290.65 to 1.940.680.08 to 1.27
    Postgraduate degree0.19−0.48 to 0.871.140.40 to 1.891.200.52 to 1.88
Maternal age at birth of the child, yb−0.10−0.15 to −0.06<.001−0.02−0.08 to 0.03.40−0.01−0.06 to 0.04.67
  • 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.