AGE AND USE OF THE EARLY CLASSIFICATION OF THE AUTISM SPECTRUM DISORDERS (ASDs) IN MULTIPLE AREAS OF THE UNITED STATES

Background: Despite the importance of early identification of children with an ASD, the Autism and Developmental Disabilities Monitoring (ADDM) Network found a median age of diagnosis between 4.5 and 5.5 years of age in 2000 and 2002 in multiple areas of the United States.

Objectives: Provide a follow-up on the age of ASD diagnosis from four sites.

Methods: The ADDM Network monitors the prevalence and population characteristics of 8-year-old children with ASDs. Four sites (portions of Arizona, Georgia, Maryland, and South Carolina) have data for at least 3 time periods. For 2004, 748 8-year-old children with ASD were confirmed via clinician review using the DSM-IV-TR criteria from existing evaluation records.

Results: Most children with ASD were receiving special education services: 86% (MD and SC), 91% (GA), 93% (AZ). They also had documented concerns about development before 3 years: 55% (MD), 79% (AZ), 83% (GA), and 85% (SC); however, the median age of earliest documented ASD diagnosis was later: 50 (SC), 60 (GA), 65 (MD), and 67 (AZ) months. From 2000 to 2004, the mdian age of earliest ASD diagnosis increased by a varying 4 to 25 months in 3 sites and decreased by 4 months in SC. However, children with ASD were more likely to have a documented classification (diagnosis or educational eligibility) of an ASD in 3 sites (GA, MD, and SC) from 2000 to 2004: 70% to 86% (GA); 70% to 89% (MD); and 30% to 58% (SC).

Conclusions: Decreases in the age of diagnosis were not found in most sites during the 4 year period; however, more children were being classified with an ASD. Therefore, evaluating progress in improving early identification may need to take into account not only the age of identification, but that more children are receiving a classification of ASD prior to the age of 8 years.