Autism Spectrum Disorder Prevalence Estimates Research Articles

Statewide county-level autism spectrum disorder prevalence estimates—seven U.S. states, 2018

Autism spectrum disorder (ASD) prevalence information is necessary for identifying community needs such as addressing disparities in identification and services. Seven Autism and Developmental Disabilities Monitoring (ADDM) Network sites participated in a pilot project to link statewide health and education data to generate statewide and county-level prevalence estimates for a broader age range for their states for the first time. Statewide prevalence of ASD for ages 3-21 years in 2018 ranged from 1.5% in Tennessee and Wisconsin to 2.3% in Arizona. The median county-level prevalence of ASD was 1.4% of residents ages 3-21 years. More boys than girls had ASD at all sites, and prevalence was lower among non-Hispanic Black, Hispanic, Asian/Pacific Islander, and American Indian/Alaska Native residents compared to non-Hispanic White residents at most sites. ASD prevalence estimates for children aged 8 years were similar to 2018 ADDM Network estimates that used record review to provide more in-depth information, but showed greater variation for children aged 4 years. Linkage of statewide data sets provides less detailed but actionable local information when more resource-intensive methods are not possible.

Understanding the Barriers to Receiving Autism Diagnoses for Hispanic and Latinx Families.

Significant disparities exist in early identification of autism spectrum disorder (ASD) for Hispanic and Latinx children. ASD prevalence estimates are approximately identical for White and Black children but lower for Hispanic and Latinx children. Reasons for these racial and ethnic variations are likely multifactorial. This review sought to understand previously described barriers and limitations to accessing ASD diagnostic services in the Latinx and Hispanic communities. Three main categories of existing barriers were identified: (1) parent/family, (2) community, and (3) systemic. These barriers are complex and multifactorial in nature, including circumstantial limitations such as limited English proficiency, noncitizenship, and low-income status. These can limit health care access, and can lead to family and community cultural barriers, poor knowledge about ASD, and social stigma related to disabilities. Understanding and mitigating barriers is essential to reduce disparities to ASD diagnosis in the Hispanic and Latinx community. [Pediatr Ann. 2022;51(4):e167-e171.].

Prevalence of autism in Europe, North America and Oceania, 2000-2020: A systematic review

Abstract Background Since the first study of the prevalence of autism spectrum disorder (ASD) in 1966, several studies from across the world have reported increasing prevalence of ASD in children. This has led to a debate whether childhood ASD cases are increasing in real time or the increase is essentially due to improved accessibility/referral to health services or changes in diagnostic criteria and accuracy. Methods MEDLINE and PSYCINFO databases were searched for studies of ASD prevalence estimates in Europe, North America and Oceania published during 2000-2020 (including prevalence data for 1993-2019). Data including age at diagnosis, gender, ethnicity, diagnostic criteria/tools, method(s) of case detection and prevalence per 10,000 population were extracted. Results 75 studies, reporting a wide range of prevalence estimates, were included in the review. Overall, there was a steady and substantial increase in the prevalence of ASD in Europe, North America and Oceania during the last three decades. For Europe, the median prevalence was 59 per 10,000 population (range, 8 to 420; mean, 80). For North America, the median prevalence was 86 per 10,000 population (range, 11 to 247; mean, 95). For Oceania, the median prevalence was 47 per 10,000 population (range, 10 to 390; mean, 112). Overall, the prevalence was higher in White children compared to other ethnic groups. Conclusions It appears that several factors can be attributed to increasing prevalence of ASD in Europe, North America and Oceania. Some of the increase is likely due to increased case ascertainment, but other factors need further investigation to determine the reason(s) for increasing prevalence of ASD. Key messages There is a wide variation in the prevalence of ASD in populations of Europe, North America and Oceania. This is partly explained by differences in case ascertainment and sociodemographic factors. The differences in prevalence between ethnic groups need further investigation.

Epidemiology of Autism Spectrum Disorders: A Review of Worldwide Prevalence Estimates Since 2014.

The prevalence of Autism Spectrum Disorder (ASD) has increased dramatically in recent decades, supporting the claim of an autism epidemic. Systematic monitoring of ASD allows estimating prevalence and identifying potential sources of variation over time and geographical areas. At present, ASD prevalence estimates are available worldwide, coming either from surveillance systems using existing health and educational databases or from population studies specifically performed. In the present article, we present a review of the ASD prevalence estimates published since 2014. Data confirm a high variability in prevalence across the world, likely due to methodological differences in case detection, and the consistent increase of prevalence estimates within each geographical area.

Assessment of racial and ethnic bias in autism spectrum disorder prevalence estimates from a US surveillance system.

This study assessed potential under-ascertainment of autism spectrum disorder due to missing administrative information for Hispanic and non-Hispanic Black children within the Autism and Developmental Disabilities Monitoring Network. We analyzed data from two Network sites (Colorado and Wisconsin) for surveillance years 2012 and 2014 to determine whether children excluded from autism spectrum disorder prevalence estimates due to missing residency and other information differed from those included by race and ethnicity. We used multiple approaches to impute missing information to evaluate impacts on racial and ethnic disparities in autism spectrum disorder prevalence. Compared with confirmed autism spectrum disorder cases, those excluded due to missing residency were more than twice as likely to be Hispanic (19% vs 44%; p < 0.002), yet the number of cases excluded due to missing residency information was too small to account for prevalence differences. Confirmation of autism spectrum disorder case status was more likely for children with relevant health records than for those with school records only. Moreover, relevant health records were more likely to be missing for Black and Hispanic children than for White children. Observed disparities in autism spectrum disorder prevalence were not accounted for by missing demographic data, but may reflect disparities in healthcare access for developmental evaluations.

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012

Autism Spectrum Disorder Diagnosis in Diagnostic and Statistical Manual of Mental Disorders-5 Compared to Diagnostic and Statistical Manual of Mental Disorders-IV.

Objectives:The objective of this study was to investigate the concordance of Diagnostic and Statistical Manual of Mental Disorders (DSM-IV and DSM-5) diagnostic criteria for autism spectrum disorder (ASD).Methods:We retrospectively reviewed the medical records of 170 subjects (age range: 3–23, 140 boys) with developmental delay or social deficit from January 2011 to July 2016 at the Department of Psychiatry of Asan Medical Center. The Autism Diagnostic Interview-Revised (ADI-R), the Autism Diagnostic Observation Schedule (ADOS), and intelligence tests were performed for each subject. Diagnosis was reviewed and confirmed for each subject with DSM-IV Pervasive Developmental Disorder (PDD) and DSM-5 ASD criteria, respectively.Results:Fifty-eight of 145 subjects (34.1%) who were previously diagnosed as having PDD in DSM-IV did not meet DSM-5 ASD criteria. Among them, 28 (48.3%) had Asperger’s disorder based on DSM-IV. Most algorithm scores on ADOS and all algorithm scores on ADI-R were highest in subjects who met both DSM-IV PDD criteria and DSM-5 ASD criteria (the Convergent group), followed by subjects with a DSM-IV PDD diagnosis who did not have a DSM-5 ASD diagnosis (the Divergent group), and subjects who did not meet either DSM-IV PDD or DSM-5 ASD criteria (the non-PDD group). Intelligence quotient was lower in the Convergent group than in the Divergent group.Conclusion:The results of our study suggest that ASD prevalence estimates could be lower under DSM-5 than DSM-IV diagnostic criteria. Further prospective study on the impact of new DSM-5 ASD diagnoses in Koreans with ASD is needed.

The Prevalence of Autism Spectrum Disorders in Adult Psychiatric Inpatients: A Systematic Review.

Background:Whilst the prevalence of autism spectrum disorders in adults within the community setting is well-established, less is known about the prevalence among adults based within a psychiatric inpatient setting.Objective:To conduct a systematic literature review pertaining to the prevalence of autism spectrum disorders among the adult psychiatric inpatient population.Method:Eligibility criteria included: (a) investigation of the prevalence of autism spectrum disorders (b) adult psychiatric inpatient study population (c) published in English language. Electronic databases accessed included PubMed, Medline, CINAHL, PsycINFO and EMBASE. Additionally, the ancestry method was utilised for the references of eligible papers, as well as grey literature searches and consultation with experts in the field.Results:From the search, 4 studies were identified which satisfied the inclusion criteria, conducted in a variety of inpatient psychiatric settings, including secure forensic and intellectual disability units and a state psychiatric hospital. There were significant differences in methodological approaches, including the screening tests, diagnostic instruments and diagnostic criteria utilised. Autism spectrum disorder prevalence estimates varied considerably, from 2.4-9.9%.Conclusion:From the limited research data currently available, it appears that the prevalence of autism spectrum disorders is increased in inpatient psychiatric settings relative to the general population. There is a need for further high quality research in this patient group, to add to this limited evidence base, as well as in developing effective strategies to identify patients with a high likelihood of autism spectrum disorders within this setting.

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

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

State-Level Trends in the Prevalence of Autism Spectrum Disorder (ASD) from 2000 to 2012: A Reanalysis of Findings from the Autism and Developmental Disabilities Network

Since 2000, the Autism and Developmental Disabilities Network (ADDM) has published detailed prevalence estimates for autism spectrum disorder (ASD) among 8 year-olds, which are widely interpreted as the U.S. national prevalence of ASD. Although differences in state-level ASD prevalence has been reported, state-level heterogeneity has not been explored systematically. We analyzed state-level estimates and trends in ASD prevalence from 2000 to 2012 using secondary data from bi-annual ADDM reports. Heterogeneity among state-level ASD prevalence estimates were apparent in 2000 and grew between 2000 and 2012. Findings highlight the need for greater understanding of how children with ASD are identified by the medical and educational systems, which has significant implications for the state-level resources required to effectively manage ASD.

European studies on prevalence and risk of autism spectrum disorders according to immigrant status-a review.

Autism spectrum disorders (ASDs), once considered to be rare, are now reaching prevalence estimates of 1% and higher. Studies conducted in North America indicate large racial/ethnic disparities in the diagnosis of ASDs. Others show, that immigrant children have similar prevalence rates of ASDs as native children, although they are diagnosed later compared with native children. In relation to a EU funded network action, Enhancing the Scientific Study of Early Autism, it was considered important to review the literature on this subject. A comprehensive literature search was undertaken for original articles reporting on prevalence and risk for ASD in Europe among immigrants and ethnic minorities and data across studies were compared. Seventeen studies conducted in Europe concerning immigrants and ethnic minorities were found. Fifteen studies suggest a higher prevalence rate of ASDs among children of immigrants in comparison to native children (RR = 1.02-1.74; OR = 0.6-10.5). One study revealed higher prevalence of autism (OR = 2.2; 95% CI 1.6-3.1) and lower prevalence of Asperger syndrome in immigrants (OR = 0.6; 95% CI 0.3-0.97). One study showed a lower prevalence of Asperger syndrome in immigrants (aOR = 0.1, 95% CI 0.01-0.5). The majority of those analyses involved immigrants from outside Europe, e.g. from Africa and South America. After analysing the results of studies conducted in Europe, it is unclear if higher prevalence estimates of ASDs among immigrants in this region reflect true differences, especially considering many potential confounding factors, e.g. genetic, biological, environmental and cultural. Considering the number of people migrating within Europe there is a substantial need to study further the prevalence of ASDs in immigrant groups.

Autism spectrum disorder reporting in lower socioeconomic neighborhoods.

Utilizing surveillance data from five sites participating in the Autism and Developmental Disabilities Monitoring Network, we investigated contributions of surveillance subject and census tract population sociodemographic characteristics on variation in autism spectrum disorder ascertainment and prevalence estimates from 2000 to 2008 using ordinal hierarchical models for 2489 tracts. Multivariable analyses showed a significant increase in ascertainment of autism spectrum disorder cases through both school and health sources, the optimal ascertainment scenario, for cases with college-educated mothers (adjusted odds ratio = 1.06, 95% confidence interval = 1.02-1.09). Results from our examination of sociodemographic factors of tract populations from which cases were drawn also showed that after controlling for other covariates, statistical significance remained for associations between optimal ascertainment and percentage of Hispanic residents (adjusted odds ratio = 0.93, 95% confidence interval = 0.88-0.99) and percentage of residents with at least a bachelor's degree (adjusted odds ratio = 1.06, 95% confidence interval = 1.01-1.11). We identified sociodemographic factors associated with autism spectrum disorder prevalence estimates including race, ethnicity, education, and income. Determining which specific factors influence disparities is complicated; however, it appears that even in the presence of education, racial and ethnic disparities are still apparent. These results suggest disparities in access to autism spectrum disorder assessments and special education for autism spectrum disorder among ethnic groups may impact subsequent surveillance.

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years--Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012.

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years--Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012.

Prevalence and Characteristics of Autism Spectrum Disorder Among 4-Year-Old Children in the Autism and Developmental Disabilities Monitoring Network

Early identification of children with autism spectrum disorder (ASD) facilitates timely access to intervention services. Yet, few population-based data exist on ASD identification among preschool-aged children. The authors aimed to describe ASD prevalence and characteristics among 4-year-old children in 5 of 11 sites participating in the 2010 Autism and Developmental Disabilities Monitoring Network. Children with ASD were identified through screening of health and education records for ASD indicators, data abstraction and compilation for each child, and clinician review of records. ASD prevalence estimates, ages at first evaluation and ASD diagnosis, cognitive test scores, and demographics were compared for 4-year-old children and 8-year-old children living in the same areas. Among 58,467 children in these 5 sites, 4-year-old ASD prevalence was 13.4 per 1000, which was 30% lower than 8-year-old ASD prevalence. Prevalence of ASD without cognitive impairment was 40% lower among 4-year-olds compared with 8-year-olds, but prevalence of ASD with cognitive impairment was 20% higher among 4-year-olds compared with 8-year-olds. Among 4-year-olds with ASD, female and non-Hispanic white children were more likely to receive their first comprehensive evaluation by age 36 months compared with male and non-Hispanic black children, respectively. Among children diagnosed with ASD by age 48 months, median age at first comprehensive evaluation was 27 months for 4-year-olds compared with 32 months for 8-year-olds. Population-based ASD surveillance among 4-year-old children provides valuable information about the early identification of children with ASD and suggests progression toward lowering the age of first ASD evaluation within participating Autism and Developmental Disabilities Monitoring communities.

Future Directions for Research in Autism Spectrum Disorders

This article suggests future directions for research aimed at improving our understanding of the etiology and pathophysiology of autism spectrum disorder (ASD) as well as pharmacologic and psychosocial interventions for ASD across the lifespan. The past few years have witnessed unprecedented transformations in the understanding of ASD neurobiology, genetics, early identification, and early intervention. However, recent increases in ASD prevalence estimates highlight the urgent need for continued efforts to translate novel ASD discoveries into effective interventions for all individuals with ASD. In this article we highlight promising areas for ongoing and new research expected to quicken the pace of scientific discovery and ultimately the translation of research findings into accessible and empirically supported interventions for those with ASD. We highlight emerging research in the following domains as particularly promising and pressing: (a) preclinical models, (b) experimental therapeutics, (c) early identification and intervention, (d) psychiatric comorbidities and the Research Domain Criteria initiative, (e) ecological momentary assessment, (f) neurotechnologies, and (g) the needs of adults with ASD. Increased research emphasis in these areas has the potential to hasten the translation of knowledge on the etiological mechanisms of ASD to psychosocial and biological interventions to reduce the burden of ASD on affected individuals and their families.

Potential Impact ofDSM-5Criteria on Autism Spectrum Disorder Prevalence Estimates

The DSM-5 contains revised diagnostic criteria for autism spectrum disorder (ASD) from the DSM-IV-TR. Potential impacts of the new criteria on ASD prevalence are unclear. To assess potential effects of the DSM-5 ASD criteria on ASD prevalence estimation by retrospectively applying the new criteria to population-based surveillance data collected for previous ASD prevalence estimation. Cross-sectional, population-based ASD surveillance based on clinician review of coded behaviors documented in children's medical and educational evaluations from 14 geographically defined areas in the United States participating in the Autism and Developmental Disabilities Monitoring (ADDM) Network in 2006 and 2008. This study included 8-year-old children living in ADDM Network study areas in 2006 or 2008, including 644 883 children under surveillance, of whom 6577 met surveillance ASD case status based on the DSM-IV-TR. Proportion of children meeting ADDM Network ASD criteria based on the DSM-IV-TR who also met DSM-5 criteria; overall prevalence of ASD using DSM-5 criteria. Among the 6577 children classified by the ADDM Network as having ASD based on the DSM-IV-TR, 5339 (81.2%) met DSM-5 ASD criteria. This percentage was similar for boys and girls but higher for those with than without intellectual disability (86.6% and 72.5%, respectively; P < .001). A total of 304 children met DSM-5 ASD criteria but not current ADDM Network ASD case status. Based on these findings, ASD prevalence per 1000 for 2008 would have been 10.0 (95% CI, 9.6-10.3) using DSM-5 criteria compared with the reported prevalence based on DSM-IV-TR criteria of 11.3 (95% CI, 11.0-11.7). Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new criteria.

Increasing autism prevalence in metropolitan New Jersey

High baseline autism spectrum disorder prevalence estimates in New Jersey led to a follow-up surveillance. The objectives were to determine autism spectrum disorder prevalence in the year 2006 in New Jersey and to identify changes in the prevalence of autism spectrum disorder or in the characteristics of the children with autism spectrum disorder, between 2002 and 2006. The cohorts included 30,570 children, born in 1998 and 28,936 children, born in 1994, residing in Hudson, Union, and Ocean counties, New Jersey. Point prevalence estimates by sex, ethnicity, autism spectrum disorder subtype, and previous autism spectrum disorder diagnosis were determined. For 2006, a total of 533 children with autism spectrum disorder were identified, consistent with prevalence of 17.4 per 1000 (95% confidence interval = 15.9-18.9), indicating a significant increase in the autism spectrum disorder prevalence (p < 0.001), between 2002 (10.6 per 1000) and 2006. The rise in autism spectrum disorder was broad, affecting major demographic groups and subtypes. Boys with autism spectrum disorder outnumbered girls by nearly 5:1. Autism spectrum disorder prevalence was higher among White children than children of other ethnicities. Additional studies are needed to specify the influence of better awareness of autism spectrum disorder prevalence estimates and to identify possible autism spectrum disorder risk factors. More resources are necessary to address the needs of individuals affected by autism spectrum disorder.

Autism spectrum disorders in the Stockholm Youth Cohort: design, prevalence and validity.

ObjectiveReports of rising prevalence of autism spectrum disorders (ASD), along with their profound personal and societal burden, emphasize the need of methodologically sound studies to explore their causes and consequences. We here present the design of a large intergenerational resource for ASD research, along with population-based prevalence estimates of ASD and their diagnostic validity.MethodThe Stockholm Youth Cohort is a record-linkage study comprising all individuals aged 0–17 years, ever resident in Stockholm County in 2001–2007 (N = 589,114). ASD cases (N = 5,100) were identified using a multisource approach, involving registers covering all pathways to ASD diagnosis and care, and categorized according to co-morbid intellectual disability. Prospectively recorded information on potential determinants and consequences of ASD were retrieved from national and regional health and administrative registers. Case ascertainment was validated through case-note review, and cross validation with co-existing cases in a national twin study.ResultsThe 2007 year prevalence of ASD in all children and young people was 11.5 per 1,000 (95% confidence interval 11.2–11.8), with a co-morbid intellectual disability recorded in 42.6% (41.0–44.2) of cases. We found 96.0% (92.0–98.4) of reviewed case-notes being consistent with a diagnosis of ASD, and confirmed ASD in 85.2% (66.2–95.8) of affected twins.ConclusionsFindings from this contemporary study accords with recently reported prevalence estimates from Western countries at around 1%, based on valid case ascertainment. The Stockholm Youth Cohort, in light of the availability of extensive information from Sweden's registers, constitutes an important resource for ASD research. On-going work, including collection of biological samples, will enrich the study further.

The role of the school psychologist in the inclusive education of school-age children with autism spectrum disorders

Two independent trends are impacting school psychologists with regard to their involvement in the education of students with autism spectrum disorders (ASDs): increasing prevalence estimates of ASDs and an emphasis on the inclusion of students with special needs in regular education classrooms. In light of these trends and growing awareness of the need for evidence-based practices in the field, school psychologists can expect to be involved in the educational programming of students with ASDs and should be knowledgeable about empirically supported strategies relevant to inclusive education of these children. The purpose of this review is to familiarize school psychologists with currently available intervention techniques by describing each strategy and outlining the degree of empirical support for each. Strategies for managing disruptive behaviors, promoting learning, and facilitating social integration are reviewed.