A new study by the Minnesota-Autism and Developmental Disabilities Monitoring Network (MN-ADDM) at the University of Minnesota identified 1 in 42 children (2.4 percent) as having autism spectrum disorder (ASD) in Minnesota. Focused on children who were 8 years old, the study relied on 2014 data from the health and special education records of 9,767 children in Hennepin and Ramsey counties.
As part of a nationwide network of studies funded by the Centers for Disease Control and Prevention’s (CDC) Autism and Developmental Disability Monitoring Network (ADDM), the Minnesota-specific study shows the rate of ASD is higher than the national average. The CDC found that, on average, 1 in 59 (1.7 percent) children was identified as having ASD in communities where prevalence was tracked by the ADDM Network. This is the first time Minnesota has been involved in the ADDM Network.
“Minnesota’s higher prevalence rates could be due, in part, to the concentration of services and supports in the Minneapolis-Saint Paul area,” said Amy Hewitt, PhD, the principal investigator for the Minnesota study.
The Minnesota study is unique in relation to other ADDM Network studies because, in addition to examining data from white, black and Hispanic populations, it also collected information on two immigrant groups with large populations in Minnesota — Somali and Hmong. The study found no significant statistical differences in prevalence rates between Somali and non-Somali children or between Hmong and other children. The prevalence finding was 1 in 26 for Somali children and 1 in 54 for Hmong children.
“While both these numbers may look very different from the overall Minnesota average of 1 in 42, the sample sizes were too small to be able to tell if these differences are real or occurred by random chance,” Hewitt said. “By being able to expand our study area beyond the borders of Hennepin and Ramsey counties in future studies, we will be able to gain a better perspective on autism rates among all Minnesotans, including those of Somali and Hmong descent.”
The Minnesota-specific study also found that:
- consistent with previous national estimates, 8-year-old boys were four times more likely to be identified with ASD than girls of the same age;
- while ASD can be diagnosed as early as age two, about half of the children tested in Hennepin and Ramsey counties were not diagnosed with ASD by a community provider until 4 years and 9 months;
- of the children with ASD who had IQ tests in their records, 43 percent of Somali children and 18 percent of Hmong children had a co-occurring intellectual disability compared to the overall average of 28 percent. Sample sizes were too small to be able to determine if this difference was real or whether it occurred by random chance.
“Understanding the prevalence of autism in Minnesota communities is a critical first step as we make plans to ensure access to services from childhood through adulthood,” said Hewitt. “We hope that as a result of the MN-ADDM project, the differences uncovered in this study will help us better understand health disparities in our state and to expand Minnesota’s autism support services and workforce network.”
The MN-ADDM Network, which is part of the Institute on Community Integration in the College of Education and Human Development at the University of Minnesota, collaborates with a wide variety of community ASD organizations and several Minnesota state organizations, including the Minnesota Departments of Education, Human Services, and Health. The MN-ADDM Network also partners with an active community advisory board.