8-year-olds

Findings from 2020 data

How many 8-year-old children were identified with ASD in Minnesota?

Using data from 2020, MN-ADDM researchers found 1 in 34 (3.0%) 8-year-old children were identified with ASD. This is comparable to the overall ADDM Network prevalence of 8-year-old children identified with ASD (1 in 36 or 2.8%) in the United States where the CDC tracked ASD in 2020.

When were children first diagnosed with ASD in Minnesota?

What was the percentage of children with ID in Minnesota?

Which children were more likely to be identified with ASD in Minnesota?

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 ASD.

*Wilson score 95% CIs exclude 1.0, indicating significantly higher prevalence.

Males had a higher ASD prevalence than females.

Hispanic children had higher ASD prevalence than White, Black, and Asian/Pacific Islander children.

What do the sex and race/ethnicity differences in prevalence rates tell us?

Males aged 8 years had a higher ASD prevalence 4.3 times higher than females aged 8 years.

Hispanic children had higher ASD prevalence than Asian/Pacific Islander, Black, and White children. Prevalence for Hispanic children was 1.7 times that of Asian/Pacific Islander children, 1.3 times that of Black children, 1.3 times that of White children. A prevalence ratio of 1.0 indicates equal prevalence rates. The confidence intervals for prevalence ratios for the above groups were all greater than 1.0, meaning these findings were very likely not due to chance.

How common is intellectual disability for 8-year-old children who have ASD?

Among children identified with ASD who had IQ information available, 32% also had intellectual disability.

• Intelligence quotient (IQ) scores were available for 86% 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 2020. In addition to the race/ethnicity categories routinely studied by CDC, in MN we are interested in understanding prevalence for children in our Hmong and Somali communities. Please check back for updated analyses including Hmong and Somali children.

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 16,150 children of the following race and ethnicity

• American Indian or Alaska Native – 1%
• Asian or Pacific Islander – 16%
• Black, non-Hispanic – 23%
• Hispanic –11%
• White, non-Hispanic—42%
• Two or more races—7%

Implications

This is the fourth time Minnesota data has been included in findings from the ADDM Network. The 2020 overall 8-year-old prevalence rate of 1 in 34 is close to the 2018 prevalence rate of 1 in 36. However, the portions of Ramsey and Hennepin counties included in prevalence estimates differed in 2018 and 2020, which may have impacted prevalence.

In Minnesota, there are differences between the proportions of males and females identified with ASD, with more males than females. This is consistent with previous estimates. (Note: the ADDM project only collects data on male and female sex as indicated in records and does not include gender identification information.)

In Minnesota, we identify ASD much later than when first concerns are reported. The median age of the first ASD diagnosis for 8-year-olds was 4 years and 11 months, which was the latest age across the ADDM Network. 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 ASD and related conditions. To learn more about the EIDBI benefit follow this link:

https://mn.gov/dhs/partners-and-providers/news-initiatives-reports-workgroups/long-term-services-and-supports/eidbi/eidbi.jsp

We found varying prevalence rates across racial and ethnic groups in Minnesota. The small number of children in some of these groups makes it difficult to determine whether the rates of children with ASD truly are different across groups. When differences are found, it is important to focus on general health disparities that may influence these differences.

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 ASD 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., 22.1–43.2 for children with two or more races). 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 ASD 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 ASD was identified, or failing to capture that the children were identified as having ASD.