8-year-olds
Findings from 2022 data
How many 8-year-old children were identified with autism in Minnesota?
Using data from 2022, MN-ADDM researchers found 1 in 28 (3.6%) 8-year-old children were identified with autism. This is comparable to the overall ADDM Network prevalence of 8-year-old children identified with autism (1 in 31 or 3.2%) in the United States where the CDC tracked ASD in 2022. This rate is higher than the rate of 1 in 34 (3.0%) that was found in 2020 in Minnesota.
Which children were more likely to be identified with ASD in Minnesota?
Males were 3.1 times more likely to be identified with autism than females
Prevalence of autism in 8-year-old children in Minnesota by U.S. Census race and ethnicity
Race and Ethnicity | Prevalence Estimate | Prevalence per 1,000 Children | 95% Confidence Interval | Prevalence Ratio Compared to White |
|---|---|---|---|---|
Overall | 1 in 28 | 35.5 | (32.9-38.4) | |
Asian/Pacific Islander | 1 in 31 | 32.6 | (26.2-40.5) | 1.1 |
Black | 1 in 24 | 41.1 | (35.5-47.4) | 1.4* |
Hispanic | 1 in 24 | 40.9 | (32.8-50.8) | 1.4* |
Multiracial | 1 in 22 | 46.0 | (35.3-59.8) | 1.6* |
White | 1 in 34 | 29.6 | (26.0-33.6) | -- |
American Indian or Alaska Native children were included in the denominator but were not included in prevalence estimations due to low numbers of children with autism.
* Significant prevalence ratio (95% CI excludes 1.0).
Black, Hispanic, and Multiracial children had higher ASD prevalence than White children.
What percentage of autistic 8-year-olds had intellectual disability?
37% had IQ less than or equal to 70
21% had IQ between 71 and 85
42% had IQ over 85
How common is intellectual disability for 8-year-old children who have ASD?
Among children identified with autism who had IQ information available, 37% also had intellectual disability.
- Intelligence quotient (IQ) scores were available for 71% of children identified with ASD by MN-ADDM. Intellectual disability is defined as IQ score ≤ 70.
This information is based on the analysis of data collected from the health and educational records of children who were 4 and 8 years old in 2022.
When were children first diagnosed with ASD in Minnesota?
Age 4 years, 7 months was the median age when children received their first clinical diagnosis of autism in Minnesota. This is later than the overall ADDM Network median age of 3 years, 11 months.
Of the children identified with autism 48.6% had an evaluation recorded by age 36 months.
Age of clinical ASD diagnosis: 4 years, 7 months
48.6% had an evaluation recorded by age 36 months
How did COVID-19 affect Evaluation and Identification of Autism in Minnesota?
To examine the effect of potential service disruption during the COVID-19 pandemic on patterns of evaluation and identification, numbers of evaluations and identifications were aggregated by calendar month for children aged 4 and 8 years in 2022. To compare the same age windows (ages 0-4 years) by calendar month, the numbers of evaluations and incidence of identification per 1,000 children from 2014 (year 0) through 2018 (year 4) for children aged 8 years was subtracted from the same months during 2018 (year 0) through 2022 (year 4) for children aged 4 years.
Children born in 2018 had more evaluations and autism identifications than children born in 2014 when comparing the two groups of children for most months during the same age window (i.e., January 2018 through December 2022 for children aged 4 years in 2022 and January 2014 through December 2018 for children aged 8 years in 2022). In March and April 2020, the first 2 months after the COVID-19 pandemic declaration, this pattern was disrupted, and the number of evaluations and rate of identification per 1,000 children was similar or lower for children born in 2018 compared with children born in 2014. Minnesota continued to show fluctuations in evaluation and identification of autism, with a period of sustained drops immediately after the pandemic through the end of 2020, some recovery in 2021 and early 2022, and a drop again during 2022.
Of the 11 ADDM sites, Minnesota had sustained declines in evaluation and identification through the end of 2020.
Tracking Area
The tracking area included parts of three counties (Anoka, Hennepin, Ramsey) including the large metropolitan cities of Minneapolis and Saint Paul.
8-year-old children in the tracking area included 17,331 children of the following race and ethnicity
- American Indian or Alaska Native – 1%
- All Asian or Pacific Islander (including Hmong) – 14%
- Black, non-Hispanic (including Somali) – 25%
- Hispanic –11%
- White, non-Hispanic—43%
- Multiracial—7%
Implications
This is the fifth time Minnesota data has been included in findings from the ADDM Network. The 2022 overall 8-year-old prevalence rate of 1 in 28 is higher than the 2020 prevalence rate of 1 in 34. Autism prevalence increased between 2020 and 2022 for females and for Asian/Pacific Islander, Black, and Multiracial children. However, the portions of Ramsey and Hennepin counties included in prevalence estimates differed in 2020 and 2022, which may have impacted prevalence.
In Minnesota, and across the ADDM network, we saw a decrease in the male-to-female ratio of autism prevalence. In the past, males typically had an autism rate 4 times higher than females. In 2022, the male : female ratio was 3.1 in Minnesota and 3.4 across ADDM sites combined. (Note: the ADDM project only collects data on male and female sex as indicated in records and does not include gender identification information.) In terms of race/ethnicity, as in 2020, we saw higher rates of autism for Hispanic children compared to White. We also saw a higher autism rate for Black and Multiracial children compared to White in 2022; these three groups had similar autism rates in 2020.
In Minnesota, we identify autism much later than when first concerns are reported. The median age of the first autism diagnosis for 8-year-olds was 4 years and 7 months,. This lag is concerning due to the critical importance of early identification and intervention. Many states, including MN, have invested in early intervention to help children and families gain access to early intervention services. For example, Minnesota’s Early Intensive Developmental and Behavioral Intervention (EIDBI) Benefit provides early intensive intervention for people with autism and related conditions. To learn more about the EIDBI benefit follow this link:
Minnesota experienced marked reductions in autism evaluations and identifications with the onset of the COVID-19 pandemic in March 2020. These reductions persisted through the end of 2020 in Minnesota, recovered for periods of 2021, and declined again in 2022.
Other states in the ADDM network showed varying patterns in the number of evaluations and identifications of autism post-pandemic [https://www.cdc.gov/mmwr/volumes/74/ss/ss7402a1.htm?s_cid=ss7402a1_w ].
Limitations
The findings in this report reflect a small number of children concentrated in a large metropolitan area and may not reflect prevalence across the entire state.
The numbers of 8-year-old children with autism from some racial/ethnic groups are small, and their prevalence estimates will be less precise than estimates for larger-sized populations. Confidence intervals show the range in which we are 95% confident that true prevalence lies, and a larger confidence interval means less precision (e.g., 39.3–59.8 for Multiracial children). This tells us we should use caution before drawing conclusions about differences between some groups.
MN-ADDM reviewed records from participating public school special education programs but did not review private school education records or all charter school education records in our geographic area. Similarly, if a child was identified with autism in a clinic outside of those included in MN-ADDM’s geographic area, their health records may not have been captured. Incomplete information could lead to misclassifying children’s cognitive ability, overestimating the age when they were first evaluated or when autism was identified, or failing to capture that the children were identified as having autism.