Intelligence quotient discrepancy indicates levels of motor competence in preschool children at risk for developmental delays

Figures & data

Table 1 Demographic characteristics of all participants (n=291)

Characteristic	Frequency
Age, months, mean (SD/range)	54.73 (10.66/30–72)
Sex, boy/girl, n (%)	204/87 (70/30)
Preterm, n (%)	44 (15)
Birth weight, n (%)
Normal birth weight (≥2,500 g)	249 (79.9)
Low birth weight (1,500 to <2,500 g)	34 (17)
Very low birth weight (<1,500 g)	8 (3.1)
Age of the fathers, years old, mean (SD/range)	37.80 (5.93/21–61)
Age of the mothers, years old, mean (SD/range)	34.00 (4.74/20–48)
Education level of the mothers, n (%)
17 years or greater (postgraduate)	5 (1.9)
13–16 years (college or technical school)	96 (36.8)
10–12 years (senior high school)	113 (43.3)
7–9 years (junior-high school)	33 (12.6)
6 years (elementary-school graduate)	11 (4.2)
Less than 6 years	3 (1.1)

Abbreviation: SD, standard deviation.

Table 2 Descriptive data and the comparison results for all participants and the three subgroups (NON group, VIQ>PIQ group, and PIQ>VIQ group) on age, FSIQ, VIQ, PIQ, and motor subtests of the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT)

	All participants (n=291)			NON groupf (n=213)			VIQ>PIQ groupf (n=39)			PIQ>VIQ groupf (n=39)			Group differences among NON, VIQ>PIQ and PIQ>VIQ groups
	Meana	SD	Range	Meana	SD	Range	Meana	SD	Range	Meana	SD	Range	F	P-value
Age (month)	54.73	10.66	30–72	54.74	10.94	30–72	56.90	10.65	32–72	52.54	8.77	35–69	1.64	0.20
FSIQb	85.50	10.62	71–131	85.02	10.82	71–131	86.69	10.50	71–117	86.31	9.68	71–112	0.57	0.57
VIQc	86.33	11.88	59–127	85.67	10.84	68–127	98.62	10.55	81–126	77.59	8.68	59–97	40.28	<0.0001**
PIQd	86.61	12.78	52–128	86.23	11.07	66–128	75.21	11.29	52–102	100.1	10.72	80–124	49.96	<0.0001**
IQDe	10.98	8.94	0–54	6.60	4.06	0–14	23.41	8.30	15–54	22.51	6.79	15–39	279.91	<0.0001**
CDIIT-gross motor	85.90	14.03	59–119	86.32	13.56	54–119	79.79	16.43	54–116	89.62	12.37	54–117	5.31	0.005**
Gravity compensation	100	0	100	100	0	100	100	0	100	100	0	100	NA	NA
Locomotion	92.49	15.87	54–117	92.82	15.22	54–117	88.05	20.61	54–115	95.15	13.26	68–117	2.14	0.12
Body-movement coordination	86.78	13.96	54–119	87.10	13.57	54–119	81.67	15.25	54–116	90.13	13.72	54–116	3.87	0.02*
CDIIT-fine motor	85.17	14.48	54–134	85.92	15.17	54–134	77.92	11.31	54–103	88.33	10.98	66–114	6.32	0.002**
Basic hand use	90.29	14.60	54–107	89.83	14.54	54–107	89.15	16.51	54–107	93.92	12.61	62–107	1.44	0.239
Visual-motor coordination	86.64	14.10	54–134	87.40	14.81	54–134	79.28	10.29	54–103	89.85	10.90	73–121	6.90	0.001**

Notes:

a Developmental quotients of the CDIIT;

b FSIQ refers to full scale intelligence quotients obtained from the Wechsler Preschool and Primary Scale of Intelligence™ – Fourth Edition (WPPSI™-IV) for presenting an overall cognitive competence;

c VIQ refers to verbal intelligence quotient obtained from the WPPSI™-IV;

d PIQ refers to performance intelligence quotient obtained from WPPSI™-IV;

e IQD refers to intelligence quotient discrepancy; absolute point value of the difference between VIQ and PIQ;

f NON group refers to IQD within 1 SD; VIQ>PIQ group refers to VIQ>PIQ above 1 SD; PIQ>VIQ group refers to PIQ>VIQ above 1 SD; 1 SD =15-point discrepancy.

* P<0.05;

** P<0.01.

Abbreviations: SD, standard deviation; IQD, intelligence quotient discrepancy; VIQ, verbal intelligence quotient, PIQ, performance intelligence quotient; NA, not applicable; FSIQ, full scale intelligence quotient; NON, IQD within 1 SD.

Table 3 Analysis with Games–Howell post hoc comparisons between subgroups, including NON group (n=213), VIQ>PIQ group (n=39), and PIQ>VIQ group (n=39)

	Groupa	Groupa	Group mean difference	SE	P-value
CDIIT-gross motor subdomain	VIQ>PIQ	NON	−6.53	2.79	0.05*
		PIQ>VIQ	−9.82	3.29	0.01*
	NON	PIQ>VIQ	−3.29	2.19	0.30
Locomotion	VIQ>PIQ	NON	−4.77	3.46	0.36
		PIQ>VIQ	−7.10	3.92	0.17
	NON	PIQ>VIQ	−2.34	2.37	0.59
Body-movement coordination	VIQ>PIQ	NON	−5.43	2.61	0.11
		PIQ>VIQ	−8.46	3.28	0.03*
	NON	PIQ>VIQ	−3.03	2.38	0.42
CDIIT-fine motor subdomain	VIQ>PIQ	NON	−7.99	2.09	0.001**
		PIQ>VIQ	−10.41	2.52	<0.001**
	NON	PIQ>VIQ	−2.42	2.04	0.47
Basic hand use	VIQ>PIQ	NON	−0.67	2.82	0.97
		PIQ>VIQ	−4.77	3.33	0.33
	NON	PIQ>VIQ	−4.10	2.25	0.17
Visual-motor coordination	VIQ>PIQ	NON	−8.12	1.94	<0.001**
		PIQ>VIQ	−10.56	2.40	<0.001**
	NON	PIQ>VIQ	−2.44	2.02	0.45

Notes:

a NON group refers to IQD within 1 SD; VIQ>PIQ group refers to VIQ>PIQ above 1 SD; PIQ>VIQ group refers to PIQ>VIQ above 1 SD; 1 SD =15 points discrepancy.

* P<0.05;

** P<0.01.

Abbreviations: CDIIT, Comprehensive Developmental Inventory for Infants and Toddlers; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient; SD, standard deviation; NON, IQD within 1 SD; SE, standard error.

Table 4 Associations between IQD and motor subtests of CDIIT for all participants and the three subgroups (NON group, VIQ>PIQ group, and PIQ>VIQ group)

	IQDa
	All participants (n=291)	NON groupb (n=213)	VIQ>PIQ groupb (n=39)	PIQ>VIQ groupb (n=39)
CDIIT-gross motor subdomain	−0.09	−0.01	−0.27	0.003
Locomotion	−0.09	−0.03	−0.29	−0.03
Body-movement coordination	−0.07	0.01	−0.31*	0.02
CDIIT-fine motor subdomain	−0.08	0.02	−0.35*	0.30
Basic hand use	0.03	−0.05	−0.02	0.17
Visual-motor coordination	−0.09	0.03	−0.46**	0.27

Notes:

a IQD refers to intelligence quotient discrepancy; absolute point value of the difference between VIQ and PIQ.

b NON group refers to IQD within 1 SD; VIQ>PIQ group refers to VIQ>PIQ above 1 SD; PIQ>VIQ group refers to PIQ>VIQ above 1 SD; 1 SD =15-point discrepancy.

* P<0.05;

** P<0.01.

Abbreviations: CDIIT, Comprehensive Developmental Inventory for Infants and Toddlers; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; SD, standard deviation; NON, IQD within 1 SD; VIQ, verbal intelligence quotient.