Prevalence of Autism Spectrum Disorders in the Public Schools

Background: Current estimates of the prevalence of autism spectrum disorders (ASD) in the U.S. are 1 in 68 (1.5%) (Christensen, 2016). However, studies indicate that many children with an ASD health diagnosis do not have an ASD special education eligibility classification within the public schools (Pinborough-Zimmerman et. al, 2012). In the past, identification of ASD within the population has been shown to vary across geographic location and race (Daniels & Mandell, 2014; OSERS, 2016).

Objectives: The purpose of this study was to examine the prevalence rates of children classified as having autism spectrum disorders in special education in the 50 states. Differences in prevalence will be considered across ages groups (i.e., ages 3-5 and 6-12) to determine if older children are more likely to be classified as having ASD within the public schools. In addition, differences across US geographic regions were considered.

Methods: Publically accessible state level Child Count and Educational Environments data from the 2014-2015 school year collected by the US Department of Education (2016) through the Individuals with Disabilities Education Act (IDEA) Section 618 was used. Data related to the number of children with eligibilities in the areas of autism spectrum disorder and significant developmental delay from the 50 states and the District of Columbia were analyzed (Age 3-5 Autism N = 66,059; age 3-5 Significant Developmental Delay N = 278,194; age 6-11 Autism N= 255,505). In addition, 2014 state population estimates for children ages 3-5 years and 6-11 years were accessed through the US Census Bureau State Characteristics Datasets (US Census Bureau, 2014).

Results: The prevalence rate for children age 3-5 with an autism eligibility was .4% and with a SDD eligibility was 2.9%. There was a significant difference between the ASD eligibility prevalence for children age 3-5 and those age 6-11 (M = .95%; p <.001). For children age 3-5 years, prevalence rates of ASD special education eligibilities are higher in the Northeast as compared to those in the Midwest (p = .015) and South (p = .016). Similarly, for children age 6-11 years, prevalence rates of ASD special education eligibilities are higher in the Northeast as compared to those in the Midwest (p = .020), South (p = .006), and West (p = .013).

Conclusions: Considering the prevalence of ASD is 1.5% of the population and only .4% of young children were found to be receiving ASD specific services in the public schools, there is considerable room for improvement in the early detection of ASD through the public school system. This is of considerable importance as young children with ASD primarily receive intervention services through the public schools (Bilaver et al., 2016). As the public schools in the Northeast US are identifying more children with ASD, it would be beneficial to further explore their processes and resource allocation in order to determine if it could be generalized.