Psychometric Properties and Derivation of Norms for an Amharic Version of Vineland Adaptive Behavioural Scale for Children with Intellectual Disability in Ethiopia

Abstract

Adaptive functions of children with intellectual disability are assessed through administration of different tools.  This study examined psychometric properties and derivation of norms for an Amharic Version of Vineland adaptive behavioural scale for children with intellectual disability in Ethiopia. The research was a cross- sectional study conducted on children with intellectual disability in Addis Ababa after obtaining an approval from Addis Ababa University. Finding of the present study revealed that, the Amharic version of VABS-II had a high overall internal consistency alpha coefficient (0.83), in the Ethiopian sample which is similar to Western findings; hence VABS-II is a reliable tool for measuring adaptive behavioural functions for children with intellectual disability. VABS II scores of Ethiopian sample were compared to the scale norms developed in the United States. Ethiopian sample means were consistently below the mean in the United States normative sample. The correlations between the VABS and Mekanyesus assessment tool composite and subdomain scores were all moderate. Even though Mekanyesus’s assessment tool didn’t follow proper procedure to prepare standardized tool like VABS-II survey form, it helped the school to assess children with intellectual disability modestly. Confirmatory factor analysis indicated that the model fit the VABS-II survey well. Thus, the Amharic version of the VABS-II survey form evidenced sound psychometric properties in Ethiopian children with intellectual disability, supporting its use in identification and intervention of children with intellectual disability.  The Amharic translated version of VABS II survey form can be used in Ethiopian context for the purpose of identification and intervention of children with intellectual disabilities. This can overcome the problem of early intervention centres, families and care givers by giving them additional assessment tool that would be used in the country

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