Translation, Validation, and Norm-Referencing of the Spanish Adaptation of the Gilliam Autism Rating Scale-2

Autism is an increasingly prevalent developmental neurological condition that manifests in pervasive impairments in social interaction, communication, and eccentric behavior and interests. Early identification leads to positive long-term outcomes. There remains an important gap in the current literature regarding standardized autism assessment instruments for Spanish speaking respondents. At present, all standardized rating instruments are written in English. The purpose of this study was to adapt the Gilliam Autism Rating Scale-2 from English into Spanish. The English instrument was translated into Spanish, back-translated into English and then revised using an iterative process. The adapted instrument was administered to 100 Spanish-speaking respondents. The participants' responses were statistically analyzed to verify the adapted instrument's internal consistency, stability reliability, discriminative validity, and construct validity. Results substantiated the psychometric qualities of the adapted instrument. An alpha coefficient of .96 verified the adapted instrument's internal consistency. Results from test-retest comparisons verified that the instrument's time stability. The instrument's discriminative validity was confirmed using analysis of variance; the autism group had significantly higher scores than did the other diagnostic groups. Factor analysis verified the construct validity as the items loaded into three clusters that corresponded to the defining characteristics of autism; social interaction, language, and stereotyped behaviors. Implications for positive social change include potentially improved autism assessment and early intervention for those children whose parents primarily speak Spanish.