Contact: Caitlin Hurley, University News Service, hurleyc@umn.edu, 612-624-1690; Tony Baisley, Institute on Community Integration, baisley@umn.edu, 612-625-4789; University News Service, unews@umn.edu, 612-624-5551

 

UMN researchers unveil Minnesota autism rates as part of nationwide CDC study

 1 in 42 children in Hennepin and Ramsey counties found to have autism

 

MINNEAPOLIS/ST. PAUL (4/26/2018) — 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, 8year-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 cooccurring 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.

For more information on the MN-ADDM Network, visit https://addm.umn.edu. To access the CDC’s nationwide ADDM Network studies, visit https://www.cdc.gov/ncbddd/autism/addm-community-report/index.html.

 

About the Institute on Community Integration:

The Institute on Community Integration is a federally-designated University Center for Excellence in Disabilities at the University of Minnesota’s College of Education and Human Development. Through collaborative research, training, and outreach, the Institute aims to improve policies and practices to ensure that all children, youth, and adults with disabilities are valued by and contribute to their communities of choice. To learn more, visit http://ici.umn.edu.

 

 

 

Key Terms

Autism spectrum disorder

Autism spectrum disorder (ASD) is a developmental disability that is caused by differences in how the brain functions. People with ASD may communicate, interact, behave, and learn in different ways. Signs of ASD begin during early childhood and usually last throughout a person’s life (1). ASD includes former diagnoses of autistic disorder, pervasive developmental disorder, not otherwise specified (PDD-NOS), and Asperger disorder. These diagnoses were collapsed into the single category of ASD in 2013.

Confidence interval

A confidence interval gives an estimated range of values which is likely to include the information (e.g., prevalence) that we want to know about.  The interval is a range of values that you can have confidence contains the true value in the population. There are different levels of confidence intervals; the most common is 95%. With a 95% confidence interval, we say that we are 95% confident that the value in our population will be included in our interval.  5% of the time, it will not.  So, we could say, “We are 95% confident that the prevalence of ASD in 8-year-olds in our surveillance area was between 21 and 27 per 1,000 children in 2014. Larger samples typically have smaller confidence intervals.  Smaller samples usually have bigger confidence intervals.

Developmental delay

A developmental delay is a persistent delay experienced by a child in reaching one or more developmental milestones—how children grow, move, communicate, interact, learn, and play.

Intellectual disability

Intellectual disability means that a person has difficulty learning at an expected level and functioning in daily life. In this report, intellectual disability is measured by intellectual quotient (IQ) test scores of less than or equal to 70.

IQ Test

A standardized psychological test or tool used to measure an individual's overall “intelligence quotient” (IQ). These tests often measureproblem-solvingg skills across a variety of domains.

Prevalence

Prevalence is a scientific term that describes the number of people with a disease or condition among a defined group at a specific period in time. Prevalence is usually expressed as a percentage or proportion of the defined group. For this project, we counted the number of 8-year-olds in 2014 who were identified with ASD and then divided that number by the total number of 8-year-olds in our surveillance area during 2014.

Statistical significance

The likelihood that a relationship between two or more variables is caused by something besides random chance.