Translation and validation of the developmental, dimensional and diagnostic interview (3Di) for diagnosis of autism spectrum disorder in Thai children

This study aimed to examine the effectiveness of a translated version of the short version of the Developmental, Dimensional and Diagnostic Interview (3Di) in discriminating children with autism spectrum disorders (ASDs) from typically developing children. Two groups, comprising 63 children with clinically ascertained ASDs and 67 typically developing children, were interviewed with the short 3Di translated version. Mean 3Di scale scores in each domain of autistic symptoms (social reciprocity, communication, and repetitive/stereotyped behaviors) were significantly higher in the ASD group than in the typically developing group. The optimal receiver operating characteristics curve cut-off scores were found to be 10, 8, and 3 for social reciprocity domain, communication domain, and repetitive/stereotyped behaviors domain, respectively, which are identical to the original English standardization. Corresponding sensitivities and specificities were 76.2% and 80.9% for the social reciprocity domain; 85.7% and 73.5% for the communication domain; and 66.7% and 80.9% for the repetitive behaviors domain. The areas under the curve were 0.89 (95% CI = 0.84-0.94), 0.88 (95% CI = 0.82-0.94), and 0.79 (95% CI = 0.71-0.87), respectively. The short 3Di-Thai version is found to be a useful diagnostic instrument for differentiating between clinically diagnosed children with ASDs and typically developing children, although further replication is needed.