Comparison of adaptive functioning measures in adolescents with autism spectrum disorder without intellectual disability

• In Event: Socio-cognitive abilities in children with Autism Spectrum Disorder

Abstract

Communication, socialization and daily living skills are important adaptive behaviors that are critical to assess when diagnosing autism spectrum disorders (ASD). Two commonly used measures include the Vineland Adaptive Behavior Scales (VABS) and the Adaptive Behavior Assessment System (ABAS). Previous work has investigated whether the second editions of these measures (VABS-II and ABAS-II, respectively) are comparable when completed by parents of children ages 6-11 years with ASD without intellectual disability (ID) (Lopata et al., 2013). However, the newest version of these measures, the VABS-3 and the ABAS-3, have yet to be compared to each other. This is important as the update versions include important changes (e.g., VABS-3 was revised to reflect advances in technology and the understanding of developmental disabilities). Additionally, there is limited research on the use of these measures to characterize adaptive functioning with older youth with ASD. Following methodology utilized by Lopata et al., 2013, this study aimed to (a) document the parent-rated VABS-3 and ABAS-3 adaptive behavior profiles of 14- to 18-year-old adolescents with ASD without ID (n=42; predominantly male and Caucasian) (within measure profile comparisons using an ipsative approach for profile comparisons); (b) examine the extent to which these measures yielded similar findings on comparable scales (cross-measure comparisons using transformed scores); and (c) assess potential discrepancies between cognitive ability and adaptive behavior as measured by the VABS-3 and ABAS-3 (using dependent samples t-tests). The overall experiment-wise alpha level was kept at .05 using a Bonferroni-corrected, per-comparison alpha level of .001 (two-tailed) across all three sets of analyses. Results showed significant adaptive skills deficits with most scores at least one SD below the mean (Table 1). Relative weaknesses were observed for social skills and relative strengths were observed for academic skills on both measures. Additionally, on the ABAS-3, relative weaknesses were observed for Leisure and relative strengths were observed for Health and Safety. Cross-measure comparisons showed the ABAS-3 generally showed the teens had better adaptive functioning than the VABS-3 showed (Table 2). Results also indicated significant discrepancies between the adolescents’ average IQ score and their scores on the two measures. Our findings are somewhat consistent with those of Lopata et al., 2013. Both studies show that adaptive functioning is impaired and significantly lower than what would be expected given their cognitive abilities in youth with ASD without ID. Although the samples could not be directly compared, the older sample in the current study showed more impaired adaptive functioning than children in the Lopata et al., 2013 study. Results of the cross-measure comparisons suggest that the absolute magnitude of scores generated by the VABS and ABAS differ, and in contrasting directions depending on the age group of youth with ASD without ID. Lopata et al., 2013, reported that the VABS-II yielded higher scores than the ABAS-II for children ages 6-11, while the current study showed the ABAS-3 yielded higher overall composite scores than the VABS-3 for adolescents ages 14-18. These findings have implications for clinicians and researchers in determining whether to use the ABAS-3 or VABS-3.

Authors

• Haley Alexis Day, Cincinnati Children's Hospital
  Presenting Author

• Leanne Tamm, Cincinnati Children's Hospital
  Non-Presenting Author

• Amie Duncan, Cincinnati Children's Hospital
  Non-Presenting Author