HealthDay News — A revised 39-item version of the Autism Symptom Dimensions Questionnaire (ASDQ) is reliable and valid for evaluating symptoms of autism, according to a study published online Jan. 11 in Developmental Medicine & Child Neurology.
Thomas W. Frazier, Ph.D., from John Carroll University in University Heights, Ohio, and colleagues describe the development and initial psychometric evaluation of the ASDQ. An initial 33-item version was developed and revised; informants administered the revised 39-item version to 1,467 children and adolescents, including 104 with autism spectrum disorder (ASD).
The researchers found good reliability and construct validity for the initial 33-item version of the ASDQ. Only four specific symptom factors were identified, possibly due to an inadequate item number. A general ASD factor and nine specific symptom factors were identified in factor analyses of the expanded instrument, with good measurement invariance across demographic groups. Good-to-excellent overall and conditional reliability was seen. Good accuracy was seen for population and at-risk contexts in exploratory analyses of predictive validity for ASD versus neurotypical and other developmental disability diagnoses.
“The instrument has potential to not only inform identification, but also has sufficient measurement precision to track individual differences from very low to very high symptom levels,” the authors write. “If the present results are replicated, the ASDQ has strong potential to be widely adopted in future research and clinical practice.”
Several authors disclosed financial ties to biopharmaceutical companies, including F. Hoffmann-La Roche and Bristol Myers Squibb, which partially funded the study.