Validation of a Japanese Version of the Vineland Adaptive Behavior Scales, Second Edition: Clinical Utility for the Assessment of Autism Spectrum Disorders

Background: At present, a comprehensive adaptive behavior scale that helps deciding the necessary level of support required for individuals with disabilities is still not available in Japan. This unavailability has led to the underestimation of the adaptive functioning needs of individuals with disabilities, particularly those who exhibit a significant disparity between their cognitive ability and adaptive functioning (i.e., those who exhibit a higher IQ but have deficits in adaptive functioning). The Vineland Adaptive Behavior Scales, Second Edition (VABS-II; Sparrow, Cicchetti, & Balla, 2005) is one of the most widely used adaptive behavior scales in the US and other countries; this scale is not only utilized for identifying individuals with cognitive disabilities, but also for assessing the needs of individuals with autism spectrum disorders (ASD) and other developmental disabilities. We have initiated a standardizing process for a Japanese version of the VABS-II.

Objectives: As part of the validation analysis, this study aimed to compare the scale scores of the Japanese version of the VABS-II among 3 groups; normal controls, individuals with ASD and intellectual disability (ID), and individuals with ASD and normal intellectual ability.

Methods: Normal controls (n = 412) were enrolled from 28 prefectures throughout Japan. The ASD with ID group (n = 81) and ASD without ID group (n = 132) were enrolled from several prefectures in central Japan. We administered the Japanese version of the VABS-II to parents, caregivers, or adult family members of individuals of the 3 groups.

Results: With regard to the adaptive behavior subscales, the ASD groups showed lower scores than the normal control group regardless of the presence of ID, especially in the Communication and Socialization domains. These differences grew more prominent with an increase in the participants’ age. With regard to the maladaptive scales, the ASD groups showed higher scores than the normal control group; however, the age of the participants was not as influential on these differences as that for the adaptive behavior scales.

Conclusions: Therefore, we observed that the Japanese version of the VABS-II is quite sensitive to the behavioral symptoms of ASD, even if the individuals have normal intellectual ability.