Table 4.

Effect of VIP on Cognitive and Language Development at 21 Months, Stratified by Level of Maternal Education

	Maternal Education <7 yr						Maternal Education ≥7 yr

	VIP (n = 35)		Control (n = 25)				VIP (n = 16)		Control (n = 17)

Measures	Mean	SD	Mean	SD	Test^a	p	Mean	SD	Mean	SD	Test^a	p
Cognitive development
MDI score	74.2	11.7	73.1	13.4	0.32	.75	81.8	12.5	70.3	11.9	2.70	.01
% Normal	22.9		16.0		0.10	.58	43.8		5.9		0.41	.02
% Borderline	48.6		52.0				43.8		64.7
% Delayed	28.6		32.0				12.5		29.4
Language development (standardized)
PLS-3 expressive score	78.5	8.0	80.0	12.2	0.56	.58	83.3	8.8	76.1	4.1	2.85	.008
% Normal	14.3		32.0		0.10	.47	43.8		0.0		0.40	.03
% Borderline	71.4		48.0				50.0		100.0
% Delayed	14.3		20.0				6.3		0.0
PLS-3 receptive score	80.6	9.8	79.7	8.7	0.36	.72	82.5	9.8	78.9	7.3	1.17	.25
% Normal	25.7		20.0		0.13	.29	25.0		20.0		0.11	.56
% Borderline	71.4		68.0				69.8		66.7
% Delayed	2.9		12.0				6.3		13.3
Language development (semistructured)
% Normal	31.4		16.7		0.27	.04	62.5		11.8		0.54	.001
% Indeterminate	57.1		50.0				31.3		52.9
% Delayed	11.4		33.3				6.3		35.3
Early Intervention eligibility
% Eligible	60.0		52.0		0.08	.55	25.0		52.9		0.29	.11

VIP, Video Interaction Project; MDI, Mental Development Index; PLS-3, Preschool Language Scale-3.

Means were compared with t-tests; ordered categorical data were compared using Spearman rank correlation (r is shown).