IQ discrepancy differentiates levels of fine motor skills and their relationship in children with autism spectrum disorders

Figures & data

Table 1 Demographic characteristics of all participants (n=127)

Characteristics	Frequency
Age, months, mean (SD/range)	51.05 (10.49/30–71)
Gender, male/female, n (%)	105/22 (83/17)
Birth weight (g), n (%)
Normal birth weight (≥2,500)	114 (89.7)
Low birth weight (1,500 to <2,500)	11 (8.7)
Very low birth weight (<1,500)	2 (1.6)
Age of the fathers in years, mean (SD/range)	37.55 (5.78/25–56)
Age of the mothers in years, mean (SD/range)	34.20 (4.76/23–47)
Education level of the mothers, n (%)
≥17 years (postgraduate)	7 (5.8)
13–16 years (some college or technical school)	56 (46.3)
10–12 years (senior high school)	42 (34.7)
7–9 years (junior-high school)	11 (9.1)
6 years (elementary-school graduate)	5 (4.1)

Table 2 Comparison among the three ASD subgroups (EVENIQ group, discrepantly higher VIQ, and discrepantly higher PIQ) on age, FSIQ, VIQ, PIQ, and motor subtests of the CDIIT

	All participants (n=127)			EVENIQ (n=81)			Discrepantly higher VIQ (n =22)			Discrepantly higher PIQ (n =24)			Group differences among EVENIQ, discrepantly higher VIQ and discrepantly higher PIQ
	Mean	SD	Range	Mean	SD	Range	Mean	SD	Range	Mean	SD	Range	F	p-value
Age (month)	51.05	10.49	30–71	50.22	11.01	30–70	49.41	9.06	36–67	55.33	9.05	33–71	2.58	0.08
FSIQ	76.43	15.40	42–131	75.41	17.26	42–131	73.45	13.25	54–106	80.58	7.22	68–101	2.56	0.13
VIQ	77.42	15.11	46–131	76.63	16.17	46–131	86.27	13.80	65–114	71.96	7.68	59–89	5.88	0.004*
PIQ	79.50	17.94	46–123	77.33	16.00	46–123	65.45	12.80	47–94	99.67	9.65	78–117	34.44	<0.0001*
IQD (absolute value)	13.12	10.45	0–52	6.70	3.69	0–14	20.82	6.76	15–44	27.71	9.26	16–52	150.27	<0.0001*
CDIIT-GM (DQs)	79.32	13.11	54–118	87.40	13.12	54–100	76.91	11.85	54–101	80.80	10.30	54–98	0.35	0.72
Gravity compensation	100	0	100	100	0	100	100	0	100	100	0	100	NA	NA
Locomotion	84.23	16.31	54–115	84.09	17.40	54–115	81.95	14.11	54–109	86.79	14.55	67–109	0.56	0.60
Body-movement coordination	81.06	12.16	54–109	81.30	12.95	54–109	79.18	11.79	54–101	81.96	9.80	60–103	0.34	0.72
CDIIT-FM (DQs)	76.54	15.16	54–112	75.70	15.60	54–112	71.14	12.36	54–92	84.61	13.27	65–112	5.10	0.008*
Basic hand use	83.60	16.33	54–108	82.09	16.63	54–108	81.91	15.60	54–107	90.48	14.72	54–107	2.57	0.08
Visual–motor coordination	78.65	14.73	54–118	77.66	14.79	54–112	73.55	11.53	54–92	86.91	14.49	67–118	5.50	0.005*

Notes: Discrepantly higher VIQ group refers to VIQ>PIQ above 1SD; discrepantly higher PIQ group refers to PIQ>VIQ above 1SD; 1SD =15 points discrepancy. EVENIQ group refers to IQD within 1SD.

* p<0.01.

Abbreviations: ASD, autism spectrum disorders; CDIIT, The Comprehensive Developmental Inventory for Infants and Toddlers; DQs, developmental quotients; FSIQ, Full Scale Intelligence Quotient; IQD, intelligence quotient discrepancy; NA, not applicable; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient; WPPSI™-IV, Wechsler Preschool and Primary Scale of Intelligence™ – Fourth Edition; 1SD, one standard deviation.

Table 3 Analysis with Bonferroni post hoc comparisons between subgroups including EVENIQ (n=81), discrepantly higher VIQ (n=22), and discrepantly higher PIQ (n=24)

DQs of the CDIIT	Groupa	Compared groupa	Group mean difference	SE p-value
CDIIT-GM	PIQ>VIQ	EVENIQ	−1.49	2.99 1.0
		VIQ>PIQ	3.05	3.67 1.0
	EVENIQ	VIQ>PIQ	1.49	3.13 1.0
Locomotion	PIQ>VIQ	EVENIQ	2.71	3.81 1.0
		VIQ>PIQ	4.84	4.83 0.96
	EVENIQ	VIQ>PIQ	2.13	3.94 1.0
Body-movement coordination	PIQ>VIQ	EVENIQ	0.66	2.84 1.0
		VIQ>PIQ	2.78	3.61 1.0
	EVENIQ	VIQ>PIQ	2.11	2.94 1.0
CDIIT-FM	PIQ>VIQ	EVENIQ	8.91	3.47 0.03*
		VIQ>PIQ	13.47	4.38 0.008**
	EVENIQ	VIQ>PIQ	4.56	3.54 0.60
Basic hand use	PIQ>VIQ	EVENIQ	8.39	3.82 0.08
		VIQ>PIQ	8.57	4.81 0.23
	EVENIQ	VIQ>PIQ	0.18	3.88 1.0
Visual–motor coordination	PIQ>VIQ	EVENIQ	9.25	3.37 0.02*
		VIQ>PIQ	13.37	4.24 0.006**
	EVENIQ	VIQ>PIQ	4.11	3.43 0.70

Notes:

a EVENIQ group refers to IQD within 1SD; discrepantly higher VIQ group refers to VIQ>PIQ of more than 1SD; discrepantly higher PIQ group refers to PIQ>VIQ of more than 1SD; 1SD =15 points discrepancy.

* p<0.05;

** p<0.01.

Abbreviations: CDIIT, The Comprehensive Developmental Inventory for Infants and Toddlers; DQs, developmental quotients; SE, standard error; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient; 1SD, one standard deviation.

Table 4 Associations between IQ profiles (ie, VIQ, PIQ, and IQD) and motor subtests of CDIIT in all participants

DQs of the CDIIT	All participants (n=127)
	IQD (PIQ – VIQ)a	VIQ	PIQ
CDIIT-GM	0.09	0.30**	0.33**
Locomotion	0.09	0.34**	0.37**
Body-movement coordination	0.07	0.23**	0.26**
CDIIT-FM	0.28**	0.41**	0.60**
Basic hand use	0.18*	0.25**	0.37**
Visual–motor coordination	0.29**	0.40**	0.60**

Notes:

a IQD (PIQ – VIQ) = Intelligence quotient discrepancy with value of the difference between PIQ and VIQ.

* p<0.05;

** p<0.01.

Abbreviations: CDIIT, The Comprehensive Developmental Inventory for Infants and Toddlers test; CDIIT-GM, gross motor skill subscale of the Comprehensive Developmental Inventory for Infants and Toddlers; CDIIT-FM, fine motor skill subscale of the Comprehensive Developmental Inventory for Infants and Toddlers; DQs, developmental quotients; IQ, intelligence quotient; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient.

Figure 1 Scatterplot showing the relationship between IQD (PIQ – VIQ) and fine motor subdomain of CDIIT (n=127).

Abbreviations: CDIIT, The Comprehensive Developmental Inventory for Infants and Toddlers; DQ, developmental quotient; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient.

Figure 2 Scatterplot showing the relationship between IQD (PIQ – VIQ) and the visual–motor coordination subtest of the CDIIT (n=127).

Abbreviations: CDIIT, The Comprehensive Developmental Inventory for Infants and Toddlers; IQD, intelligence quotient discrepancy; PIQ, performance intelligence quotient; VIQ, verbal intelligence quotient.