Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020.
Level 4 - case-series / case-control
Multi-site cross-sectional active surveillance study based on health and education record abstraction.
PubMed 36952288 · doi:10.15585/mmwr.ss7202a1
What was done
The CDC Autism and Developmental Disabilities Monitoring (ADDM) Network conducted active surveillance in 2020 to estimate autism spectrum disorder (ASD) prevalence among 8-year-old children across 11 US sites (Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin). ADDM staff reviewed and abstracted developmental evaluations and records from community medical and special education service providers. Children met the case definition if records documented an ASD diagnostic statement, an ASD special education classification, or an ASD ICD code.
What was found
Overall ASD prevalence was 27.6 per 1,000 (one in 36) children aged 8 years, ranging from 23.1 in Maryland to 44.9 in California. Prevalence was 3.8 times higher in boys than girls (43.0 vs. 11.4 per 1,000). ASD prevalence per 1,000 was 33.4 in Asian/Pacific Islander, 31.6 in Hispanic, 29.3 in Black, 26.5 in American Indian/Alaska Native, 24.3 in White, and 22.9 in children of two or more races. Among 6,245 identified cases, 74.7% had a documented diagnosis, 65.2% had a special education classification, 71.6% had an ICD code, and 37.4% had all three indicators. Median age at earliest known diagnosis was 49 months (range: 36 months in California to 59 months in Minnesota). Among 4,165 children with cognitive data, 37.9% were classified as having an intellectual disability, with higher rates among Black (50.8%) than White (31.8%) children.
Why it matters
This surveillance report establishes that US ASD prevalence rose to 1 in 36 children by 2020. It also documents a shift from historical patterns, showing higher measured prevalence in Black, Hispanic, and Asian/Pacific Islander children compared with White children.
Limits
Ascertainment was based entirely on existing health and special education records rather than direct clinical evaluations, making it sensitive to local documentation and access patterns. The 11 regional sites are not nationally representative. Data on cognitive ability were missing for 33.3% (2,080 of 6,245) of identified cases, and total population denominator numbers were not provided in the abstract.
Cited by
- context 1 in 31 American children have autism.