Cognitive-adaptive functioning gap and mediating factors impact on adaptive functioning in preschool-aged children with autism spectrum disorder: a retrospective study

Abstract

Background Few studies have focused on cognitive-adaptive functioning gap in autism spectrum disorder (ASD), and how mediating factors impact on adaptive functioning remains undefined. This study aims to investigate the gap between cognitive functioning and adaptive functioning in preschool-aged children with ASD, especially in verbal and non-verbal intelligence quotient (IQ) level. Mediating factors of cognitive functioning, ASD severity, early development and socioeconomic factors are systematically explored to determine adaptive functioning. Methods A total of 151 children with ASD were enrolled, aged 2.5-6 years. Adaptive Behavior Assessment System Version II (ABAS-II)，Wechsler Preschool and Primary Scale-IV (WPPSI-IV), Autism Diagnostic Observation Schedule (ADOS) were respectively performed to assess adaptive functioning, cognitive functioning and ASD severity. All children were divided into two groups based on IQ: IQ≥70 group and IQ<70 group. The difference of IQ-adaptive skills gap between the two groups were explored by calibrating age, age of diagnosis and IQ. Verbal acceptation index (VAI) and nonverbal index (NVI) were distinguished to predict adaptive skills. Results The gap between IQ and adaptive skills was significant in ASD with IQ≥70, and the differences in VIA and NVI were still statistically significant (all P<0.001). VIA was positively association with overall adaptive skills and specific domain, whereas NVI had no significant correlations with adaptive skills. Despite ADOS-Calibrated severity scores were negatively correlated with social and practical skills, the scores accounted for no significant variance. Age of first walking unaided was positively correlation with adaptive skills and specific domain (all P<0.05). Conclusions The IQ-adaptive functioning gap is significant in ASD with IQ≥70, suggesting that "high functioning autism" is not an appropriate description merely on account of IQ. Verbal IQ is a specific factor to predict adaptive functioning of ASD; The severity of ASD symptoms have no significant contribution to predict adaptive functioning; Early signs of motor development may be a predictor to adaptive functioning in preschool-aged children with ASD.