Table 3.

Associations of subscales of the Early Child Behavior Questionnaire and expressive language scores at 40 months: regression coefficients in z-score (change in SD), 95% confidence intervals and p-values

	Model 1		Model 2		Model 3
	Coefficient [95%CI]	p	Coefficient [95%CI]	p	Coefficient [95%CI]	p
Motor activation	−0.192 [−0.274, − 0.109]	< .001	−0.234 [− 0.331, − 0.137]	< .001	− 0.211 [− 0.305, − 0.117]	< .001
Perceptual sensitivity	0.144 [0.079, 0.209]	< .001	0.157 [0.079, 0.236]	< .001	0.137 [0.061, 0.213]	< .001
Inhibitory control	0.190 [0.115, 0.265]	< .001	0.110 [0.024, 0.195]	.01	0.091 [0.009, 0.173]	.029
Soothability	0.119 [0.048, 0.189]	.001	0.028 [−0.055, 0.110]	.51	0.024 [− 0.054, 0.103]	.55
Attentional shifting	0.232 [0.146, 0.317]	< .001	0.095 [−0.005, 0.194]	.06	0.087 [−0.008, 0.182]	.07
Low-intensity pleasure	0.206 [0.116, 0.296]	< .001	0.105 [0.008, 0.202]	.034	0.066 [−0.026, 0.159]	.16

Note. Model 1 = Univariate; Model 2 = Adjusted for other subscales of the Early Child Behavior Questionnaire Subscales (ECBQ); Model 3 = Model 2 with further adjustment for child sex, birth weight, gestational age at birth, birth order, age of the mother, years of maternal education, annual household income, maternal history of mood/anxiety disorders. CI Confidence intervals. Bold types represent p < .0013. The regression coefficients shown in Table 3 indicate the amount of predicted change in the z-score of expressive language skills per one unit of change in each of the ECBQ subscales. The marginal magnitude of difference was calculated as follows: a child scoring 7 (maximum) in motor activation, for example, was predicted to score − 0.211 × 6 (i.e., 7 minus 1 point in the subscale) = − 1.266 points, corresponding to − 1.266 SD higher lower in the expressive language skill score at 40 months compared with a child scoring 1 (minimum)