Saturday, May 9, 2009
Northwest Hall (Chicago Hilton)
11:00 AM
Background: Prior studies have found the specificity of autism spectrum disorder (ASD) diagnoses in communities to be high; the methodology of recent prevalence studies is predicated on this assumption. Studies of specificity of diagnosis, however, are more than a decade old. As awareness and community resources for ASD increase, the number of false positives could increase. Understanding the frequency of and factors associated with false positives could help in the interpretation of recent epidemiologic studies and guide strategies to ensure appropriate diagnosis in community settings.
Objectives: To determine whether children placed in autism support classrooms who had received autism support services prior to entering kindergarten also met diagnostic criteria for an ASD using gold-standard evaluation tools.
Methods: The sample included 166 ethnically and economically diverse children in 42 kindergarten-to-second-grade autism support classrooms in one large urban school district. These children received extensive baseline evaluations as part of a larger intervention trial. Evaluations were completed at the beginning of the school year prior to the start of academic programming and included assessment of autism symptoms via direct observation with the Autism Diagnostic Observation Schedule, parent report on the Social Responsiveness Scale, and teacher report on the Pervasive Developmental Disorders Behavior Inventory. Additional information on adaptive functioning, cognitive development, and use of community services also was obtained.
Results: Preliminary findings suggested that approximately 11% of the sample did not meet current criteria for an ASD on the ADOS. Ongoing analyses are examining factors associated with diagnostic outcome, such as age of diagnosis, participation in early intervention, intensity of interventions, receipt of ancillary services, socioeconomic status, co-occurring medical or developmental problems (e.g., hearing impairment, speech and language delay), and bilingualism.
Conclusions: These findings and their implications for specificity of ASD diagnosis in community samples, as well as factors that may increase a false diagnosis of autism in elementary school age children will be discussed. Possible strategies for future estimation of ASD community prevalence will also be presented. Methodological limitations, including reliance on direct observation versus parent report of symptoms will be considered.
Objectives: To determine whether children placed in autism support classrooms who had received autism support services prior to entering kindergarten also met diagnostic criteria for an ASD using gold-standard evaluation tools.
Methods: The sample included 166 ethnically and economically diverse children in 42 kindergarten-to-second-grade autism support classrooms in one large urban school district. These children received extensive baseline evaluations as part of a larger intervention trial. Evaluations were completed at the beginning of the school year prior to the start of academic programming and included assessment of autism symptoms via direct observation with the Autism Diagnostic Observation Schedule, parent report on the Social Responsiveness Scale, and teacher report on the Pervasive Developmental Disorders Behavior Inventory. Additional information on adaptive functioning, cognitive development, and use of community services also was obtained.
Results: Preliminary findings suggested that approximately 11% of the sample did not meet current criteria for an ASD on the ADOS. Ongoing analyses are examining factors associated with diagnostic outcome, such as age of diagnosis, participation in early intervention, intensity of interventions, receipt of ancillary services, socioeconomic status, co-occurring medical or developmental problems (e.g., hearing impairment, speech and language delay), and bilingualism.
Conclusions: These findings and their implications for specificity of ASD diagnosis in community samples, as well as factors that may increase a false diagnosis of autism in elementary school age children will be discussed. Possible strategies for future estimation of ASD community prevalence will also be presented. Methodological limitations, including reliance on direct observation versus parent report of symptoms will be considered.