TABLE 3

Adjusted Individual Growth Models for Longitudinal Changes in WISC-III Vocabulary, WISC-III Block-Design, and PPVT-R Raw Scores and Effects of Preterm Birth and Gender on Growth From 8 Through 16 Years of Age

Parameters and Growth PredictorsWISC-III Vocabulary Subtest, Estimate (SE)WISC-III Block Design Subtest, Estimate (SE)PPVT-R, Estimate (SE)
Fixed effects
    Initial status
        Intercept23.5 (1.5)a27.6 (2.6)a99.0 (5.3)a
        Preterm birth−5.5 (1.5)a−7.8 (2.5)a−14.4 (5.1)b
        Male gender2.3 (2.0)7.1 (3.4)b3.1 (7.0)
        Preterm birth × male−2.9 (2.1)−7.5 (3.6)−4.2 (7.4)
Rate of change9.8 (0.8)a13.3 (1.2)a19.1 (1.7)a
    Age, y
        Age × preterm birth0.3 (0.8)−0.9 (1.2)4.0 (1.8)b
        Age × male−1.7 (1.1)−2.6 (1.7)−0.3 (2.5)
        Age × preterm birth × male1.9 (1.2)2.8 (1.8)−0.9 (2.6)
  • Models are adjusted for the level of maternal education, minority status, and single-parent household.

  • a P < .001.

  • b P < .05.