Korean J Pediatr.  2004 May;47(5):496-504.

The Relationship between Developmental Quotient in Children with Delayed Language Development and Later Intellectual Quotient

• Kim SY
• Jung YK
• Jung HL
• Kim WT
• Shin IH
• Park JH
• Kim HM
• Kim JK

Abstract

PURPOSE
The objective of this study was to test the predictive validity of developmental test for later intellectual development in young children with delayed language development.
METHODS
The study subjects were 66 children who had presented delayed language development and had an initial developmental test and a follow-up intelligence test. The mean age at initial test was 34.2 months(17-48 months), and the mean age at the follow-up test was 55.0 months(40-79.5 months).
RESULTS
According to CAT DQ(Cognitive Adaptive Test Developmental Quotient), 66 children were divided into 4 groups: group I(CAT DQ<50), group II(50-69), group III(70-84), and group IV(> = or85). There was a moderate correlation between CAT DQ and later total IQ in group I(r=0.58) and II(r= 0.50), but a low correlation in group III(r=0.19) and IV(r=-0.16). IQs in follow-up tests of all children in group I and II were lower than 70, except two children whose IQs were 75 and 78. IQs of children in group III were lower than 85 except for three children whose IQs were 89, 89, and 90, respectively.
CONCLUSION
The findings of this study suggest that if DQ is lower than 70, the child is highly probable to be mentally subnormal in later years. Although the correlation between CAT DQ and later total IQ is low in children with DQs over 70, if a DQ is between 70 and 84, the child is very likely to have learning disability in later years.

Keyword

Language delay; Developmental quotient; Intelligence quotient

MeSH Terms

Animals
Cats
Child*
Follow-Up Studies
Humans
Intelligence Tests
Language Development Disorders
Language Development*
Learning Disorders