Clinical distinctions in diagnostic subtypes of autism spectrum disorders vary between sites
TUESDAY, Nov. 8 (HealthDay News) -- Best-estimate clinical diagnoses of different diagnostic subtypes of autism spectrum disorders vary widely across sites, according to a study published online Nov. 7 in the Archives of General Psychiatry.
Catherine Lord, Ph.D., from Weill Cornell Medical College in White Plains, N.Y., and colleagues investigated the variation in the correlation between behavioral phenotypes and clinical diagnoses of different autism spectrum disorders across 12 university-based sites. Phenotype data (diagnostic, developmental, and demographic) were collected and classification trees were used to identify characteristics that were predictive of diagnoses across and within sites. A total of 2,102 probands between the ages of 4 and 18 years who met autism spectrum criteria on the Autism Diagnostic Interview-Revised and the Autism Diagnostic Observation Schedule and had a clinical diagnosis of an autism spectrum disorder were included. The main outcome measured was the best-estimate clinical diagnoses predicted by standardized scores based on diagnostic, cognitive, and behavioral measures.
The investigators found that the distributions of scores on standardized measures were similar across sites. However, with respect to the best-estimate clinical diagnoses of specific autism spectrum disorders, there were significant site differences. There was variation across sites in weighting of information and cut-offs for the correlation between clinical diagnoses and standardized scores, especially for verbal IQ, language level, and core diagnostic features.
"Clinical distinctions among categorical diagnostic subtypes of autism spectrum disorders were not reliable even across sites with well-documented fidelity using standardized diagnostic instruments," the authors write.
One of the study authors disclosed financial ties to the manufacturer of the diagnostic instruments used in this study.
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