The assessment of children with autism spectrum disorders is going high tech.
The Developmental, Dimensional and Diagnostic Interview, known as 3di, is a computerized program that analyzes autistic symptoms in clinical and normal populations, said David Skuse, M.D., of University College London and his colleagues.
Current standardized interviews, including the National Institute of Mental Health Diagnostic Interview Schedule for Children, fail to measure autistic symptoms, the researchers noted.
Although nothing substitutes for a careful interview by someone who knows the child well, the 3di is a hybrid of structured and semistructured interview methods (J. Am. Acad. Child Adolesc. Psychiatry 2004;43:548–58).
The program is meant primarily to evaluate autistic traits in children with normal-range abilities, but it includes features to assess children with moderate or severe mental retardation as well, the researchers said.
In terms of concurrent validity, the 3di was nearly perfect in determining whether children had any autism diagnosis: Among 60 cases and 60 comparison children (mean age 11 years), the 3di diagnosed only one comparison patient with generalized autism disorder.
In a second approach to concurrent validity involving 60 symptomatic children who were referred to psychiatric services, 27 had clinician-diagnosed autism spectrum disorders. Based on how well the children met the International Statistical Classification of Diseases, the 3di program diagnosed 29 of the children with a significant autistic disorder. In addition, the 3di's positive predictive power was 0.93 and negative predictive power was 0.91 in a discriminant validity study of the program's ability to distinguish autism spectrum disorders from nonautistic conditions.
Dr. Skuse is a stockholder in IXDX Ltd., which owns the rights to the interview software and to the dissemination of the technology.