Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years – Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014

PROBLEM/CONDITION: Autism spectrum disorder (ASD).

PERIOD COVERED: 2014.

DESCRIPTION OF SYSTEM: The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance system that provides estimates of the prevalence of autism spectrum disorder (ASD) among children aged 8 years whose parents or guardians reside within 11 ADDM sites in the United States (Arizona, Arkansas, Colorado, Georgia, Maryland, Minnesota, Missouri, New Jersey, North Carolina, Tennessee, and Wisconsin). ADDM surveillance is conducted in two phases. The first phase involves review and abstraction of comprehensive evaluations that were completed by professional service providers in the community. Staff completing record review and abstraction receive extensive training and supervision and are evaluated according to strict reliability standards to certify effective initial training, identify ongoing training needs, and ensure adherence to the prescribed methodology. Record review and abstraction occurs in a variety of data sources ranging from general pediatric health clinics to specialized programs serving children with developmental disabilities. In addition, most of the ADDM sites also review records for children who have received special education services in public schools. In the second phase of the study, all abstracted information is reviewed systematically by experienced clinicians to determine ASD case status. A child is considered to meet the surveillance case definition for ASD if he or she displays behaviors, as described on one or more comprehensive evaluations completed by community-based professional providers, consistent with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) diagnostic criteria for autistic disorder; pervasive developmental disorder-not otherwise specified (PDD-NOS, including atypical autism); or Asperger disorder. This report provides updated ASD prevalence estimates for children aged 8 years during the 2014 surveillance year, on the basis of DSM-IV-TR criteria, and describes characteristics of the population of children with ASD. In 2013, the American Psychiatric Association published the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), which made considerable changes to ASD diagnostic criteria. The change in ASD diagnostic criteria might influence ADDM ASD prevalence estimates; therefore, most (85%) of the records used to determine prevalence estimates based on DSM-IV-TR criteria underwent additional review under a newly operationalized surveillance case definition for ASD consistent with the DSM-5 diagnostic criteria. Children meeting this new surveillance case definition could qualify on the basis of one or both of the following criteria, as documented in abstracted comprehensive evaluations: 1) behaviors consistent with the DSM-5 diagnostic features; and/or 2) an ASD diagnosis, whether based on DSM-IV-TR or DSM-5 diagnostic criteria. Stratified comparisons of the number of children meeting either of these two case definitions also are reported.

RESULTS: For 2014, the overall prevalence of ASD among the 11 ADDM sites was 16.8 per 1,000 (one in 59) children aged 8 years. Overall ASD prevalence estimates varied among sites, from 13.1-29.3 per 1,000 children aged 8 years. ASD prevalence estimates also varied by sex and race/ethnicity. Males were four times more likely than females to be identified with ASD. Prevalence estimates were higher for non-Hispanic white (henceforth, white) children compared with non-Hispanic black (henceforth, black) children, and both groups were more likely to be identified with ASD compared with Hispanic children. Among the nine sites with sufficient data on intellectual ability, 31% of children with ASD were classified in the range of intellectual disability (intelligence quotient [IQ] <70), 25% were in the borderline range (IQ 71-85), and 44% had IQ scores in the average to above average range (i.e., IQ >85). The distribution of intellectual ability varied by sex and race/ethnicity. Although mention of developmental concerns by age 36 months was documented for 85% of children with ASD, only 42% had a comprehensive evaluation on record by age 36 months. The median age of earliest known ASD diagnosis was 52 months and did not differ significantly by sex or race/ethnicity. For the targeted comparison of DSM-IV-TR and DSM-5 results, the number and characteristics of children meeting the newly operationalized DSM-5 case definition for ASD were similar to those meeting the DSM-IV-TR case definition, with DSM-IV-TR case counts exceeding DSM-5 counts by less than 5% and approximately 86% overlap between the two case definitions (kappa = 0.85).

INTERPRETATION: Findings from the ADDM Network, on the basis of 2014 data reported from 11 sites, provide updated population-based estimates of the prevalence of ASD among children aged 8 years in multiple communities in the United States. The overall ASD prevalence estimate of 16.8 per 1,000 children aged 8 years in 2014 is higher than previously reported estimates from the ADDM Network. Because the ADDM sites do not provide a representative sample of the entire United States, the combined prevalence estimates presented in this report cannot be generalized to all children aged 8 years in the United States. Consistent with reports from previous ADDM surveillance years, findings from 2014 were marked by variation in ASD prevalence when stratified by geographic area, sex, and level of intellectual ability. Differences in prevalence estimates between black and white children have diminished in most sites, but remained notable for Hispanic children. For 2014, results from application of the DSM-IV-TR and DSM-5 case definitions were similar, overall and when stratified by sex, race/ethnicity, DSM-IV-TR diagnostic subtype, or level of intellectual ability.

PUBLIC HEALTH ACTION: Beginning with surveillance year 2016, the DSM-5 case definition will serve as the basis for ADDM estimates of ASD prevalence in future surveillance reports. Although the DSM-IV-TR case definition will eventually be phased out, it will be applied in a limited geographic area to offer additional data for comparison. Future analyses will examine trends in the continued use of DSM-IV-TR diagnoses, such as autistic disorder, PDD-NOS, and Asperger disorder in health and education records, documentation of symptoms consistent with DSM-5 terminology, and how these trends might influence estimates of ASD prevalence over time. The latest findings from the ADDM Network provide evidence that the prevalence of ASD is higher than previously reported estimates and continues to vary among certain racial/ethnic groups and communities. With prevalence of ASD ranging from 13.1 to 29.3 per 1,000 children aged 8 years in different communities throughout the United States, the need for behavioral, educational, residential, and occupational services remains high, as does the need for increased research on both genetic and nongenetic risk factors for ASD.

This podcast is dedicated to siblings of people with autism who are typically developing. They play an important and beneficial role in development of socialization of those with ASD. But sadly, they also have issues of their own, such as a high rate of issues like anxiety and depression. Those siblings may be genetic carries of a specific mutation and not have an autism diagnosis, but have increased risk for schizophrenia and cognitive disability. Finally, just because they are considered “typically developing” doesn’t mean they don’t have challenges with adaptive behavior. However, they have a very special relationship with their brothers and sisters, and the world needs these strong advocates for the community.

Recently, Clare Harrop from University of North Carolina at Chapel Hill published two papers which help explain the differences between boys and girls with autism, at least in kids and toddlers. She graciously agreed to talk with ASF about these findings and what it means for better identification and diagnosis of girls with ASD, and where future research is needed, for this week’s podcast. Thank you to Dr. Harrop for this insight and for your work in this area!

Children are not small adults, and this was illustrated this week in two papers studying features of autism across the lifespan. Their symptoms may change, which has implications for treatment – you can’t take an intervention designed for a child and give it to an adult. Hear more on this week’s podcast with an interview with Vanessa Hus-Bal from the new Rutgers University center on autism in adults. Also included is a new study from Julie Lounds Taylor about the stress response in adolescents vs. adults.

Two weeks ago, the autism research community lost a pioneer, mentor and advocate for the autism community. This podcast only highlights a portion of the enormous contribution he made to autism research and the impact his research had on families with ASD. Also, two people that know him best, one of his current mentees, Suzannah Iadarola and his wife, Jennifer Katz, reflect on his dedication and commitment to families of all ages. He will be missed.

On this week’s podcast, highlights from the Phelan-McDermid Syndrome Foundation 2018 International Family Conference in Dallas, TX. People with Phelan McDermid Syndrome, or PMS, suffer from seizures and intellectual disability, and about 70% have an ASD diagnosis. This syndrome is caused by mutations of the SHANK3 gene, which is present in about 1% of people with autism, making it the most common single genetic influence of ASD. Learn more about the conference here.

By Meghan Miller, PhD

Kids playing with a tablet

More and more, researchers and clinicians are thinking about how advances in technology can be leveraged for interventions for children with autism. Tablets, computers, and video games have become increasingly available to children in their daily lives. At the same time, the American Academy of Pediatrics has put forth clear screen time guidelines for children, and many parents worry about their children spending too much time in front of a screen or with devices.

In the autism field, technology is providing promising avenues for early detection and intervention. For example, a recent study describes the use of mobile technology to screen for autism in young children. Others have developed apps and virtual reality systems through which treatments can be delivered. But what good are advances in technology-based interventions if parents aren’t interested in utilizing them?

Researchers at the UC Davis MIND Institute on the UC Davis Medical Center campus in Sacramento are conducting a study of parental perceptions of use of technology in treatment of impulsivity in 4 to 7-year-olds with autism spectrum disorder. Parents of 4 to 7-year-old children who have been diagnosed with autism spectrum disorder (ASD) can participate. Families can expect to complete of several online questionnaires about: Your family, your opinions about technology in treatment, and your child’s behavior. These questionnaires will take about 10 minutes of your time.

Take our survey: http://bit.ly/autismtechsurvey

Learn more here: https://studypages.com/s/technology-in-treatment-study-364017/