Association between Cognitive Abilities before the Age of 3 Years and Those at Least 1 Year Later in Children with Developmental Delay.

Objective: This study investigated whether early cognitive assessment in children with developmental delay (DD) predicts cognitive development. We investigated the correlation between cognitive and language development in children with DD, cerebral palsy (CP), and autism spectrum disorder (ASD).

Methods: Data were collected from children diagnosed with DD who visited the hospital between 2015 and 2023. The assessments included the Korean Bayley Scales of Infant and Toddler Development Second Edition (K-BSID-II) and the Korean Wechsler Preschool Primary Scale of Intelligence Fourth Edition (K-WPPSI-IV). Language development was evaluated using the Sequenced Language Scale for Infants (SELSI) and Preschool Receptive-Expressive Language Scale (PRES). The statistical analysis involved a correlation analysis.

Results: Among 95 children in the study, a significant correlation was discovered between early cognitive assessments (the Mental Developmental Index from the K-BSID-II) and later cognitive development (the Full-Scale Intelligence Quotient from the K-WPPSI-IV) in the DD and CP groups, but not in the ASD group. The DD and CP groups exhibited significant correlations in language development between the SELSI and PRES, whereas the ASD group did not.

Conclusion: Early cognitive assessments can predict later cognitive development in children with DD and CP, but not in those with ASD, according to this study. There was a strong correlation between language and cognitive development in the DD and CP groups, highlighting the importance of early intervention and assessment for these children. Further investigation is necessary to address these limitations and refine demographic data.