Table 3.

Hierarchical linear regressions: prediction of cognitive task performance by maternal smoking during pregnancy (MSP), birth weight, and sociodemographic factors

Outcome variable	Independent variable(s)	B	SE	β	p
WPPSI-R blocks
Block 1	MSP	−0.10	0.033	−0.075	0.003
Block 2	MSP	−0.09	0.034	−0.070	0.006
	Birth weight	0.03	0.026	0.027	0.297
Block 3 (stepwise)a	MSP	−0.01	0.035	−0.006	0.826
	Birth weight	0.02	0.026	0.020	0.440
	Maternal education	0.13	0.029	0.136	< 0.001
	Family income	0.09	0.029	0.087	0.003
PPVT
Block 1	MSP	−0.17	0.034	−0.126	< 0.001
Block 2	MSP	−0.16	0.035	−0.118	< 0.001
	Birth weight	0.05	0.027	0.046	0.073
Block 3 (stepwise)b	MSP	−0.01	0.035	−0.006	0.805
	Birth weight	0.04	0.026	0.035	0.153
	Maternal education	0.21	0.029	0.208	< 0.001
	Responsiveness	0.13	0.029	0.111	< 0.001
	Family income	0.13	0.029	0.126	< 0.001
	Family dysfunction	−0.06	0.028	−0.055	0.024
VCR
Block 1	MSP	−0.17	0.035	−0.121	< 0.001
Block 2	MSP	−0.15	0.035	−0.111	< 0.001
	Birth weight	0.06	0.027	0.061	0.018
Block 3 (stepwise)c	MSP	−0.04	0.036	−0.028	0.296
	Birth weight	0.05	0.027	0.051	0.041
	Maternal education	0.18	0.030	0.176	< 0.001
	Family income	0.09	0.030	0.088	0.002
	Responsiveness	0.07	0.030	0.058	0.021

Data courtesy of the Institut de la Statistique du Québec.

^aFinal model WPPSI-R blocks (Wechsler Preschool and Primary Scale of Intelligence-Revised block design): F(4, 1536) = 16.2, p<0.001, R² = 0.041, excluded variables: responsiveness, involvement, family dysfunction.

^bFinal model PPVT (Peabody Picture Vocabulary Test): F(6, 1534) = 36.1, p<0.001, R² = 0.124, excluded variable: involvement.

^cFinal model VCR (Visually Cued Recall): F(5, 1535) = 24.0, p<0.001, R² = 0.072, excluded variables: involvement, family dysfunction.