Research explores autism prevalence among children

How common is autism spectrum disorder among children? Recent studies show that’s a complex question, and the answer can vary significantly by variables such as geographic location, race and cultural group.

Now, University of Minnesota researchers are working on a large-scale effort to better understand how autism prevalence varies across communities in the Twin Cities. The Minnesota Autism and Developmental Disabilities Monitoring Network (MN-ADDM), led by the U’s Institute on Community Integration, will study up to 3,500 records from across a group of 20,000 8-year-olds across Hennepin and Ramsey counties to track the rate of those with autism as well as those with intellectual disabilities, which researchers suspect may correlate with autism among certain demographics.

The Minnesota project, which started in early 2015, is the latest addition to a national network of ADDM sites established and funded by the Centers for Disease Control and Prevention to monitor autism prevalence in regions across the country.

“It’s really important on a lot of levels for Minnesota to have an ADDM site,” said Jennifer Hall-Lande, Ph.D., project director for MN-ADDM and research associate with ICI. “The project helps us build connections both with our local communities and the larger national trends to more thoroughly understand autism prevalence.”

Researchers with MN-ADDM are now collecting data from school systems and medical clinics to identify how many children show an “eligibility” for autism — an estimate of autism status based on a child’s documented behaviors. While not all children with autism have been clinically diagnosed, measuring behavioral characteristics and reviewing educational assessment data can provide a wide view of how many children show signs of autism.

The study begins with data abstractors, who review a large collection of school records and clinical assessments to identify children who show behavioral signs of autism and those demonstrating signs of intellectual disabilities. The abstractors will pass these records to licensed school and clinical psychologists, like Hall-Lande and Amy Esler, Ph.D., assistant professor with the U’s Center for Neurobehavioral Development, who will decide whether each case meets the defined eligibility criteria for autism. The records that do will then be flagged for Jen Poynter, Ph.D., epidemiologist with the U’s School of Public Health, for analysis.

Amy Hewitt, Ph.D., principal investigator for MN-ADDM and senior research associate with ICI, said one of the project’s greatest strengths is that it brings together experts from a wide range of disciplines, including public health, pediatrics, psychology, special education, social work, health care and public policy.

“MN-ADDM staff come from very different backgrounds and see issues related to supports and services for people with autism and their families through different lenses,” she said. “This transdisciplinary approach provides a focus that extends beyond gathering data in a reliable and valid way; it allows us to also focus on community engagement and understanding how to support children with autism, their families and their communities.”

The MN-ADDM project follows an earlier U study focused on autism and intellectual disabilities prevalence in 7- to 9-year-olds in Minneapolis. The 2013 study aimed examined parents and educators’ concerns that Somali children were disproportionately likely to be identified with autism. Researchers found autism prevalence in Somali children was about equal to white children, but both groups showed higher prevalence than Hispanic and non-Somali black children. The study also found Somali children with autism were significantly more likely than those in other groups to have intellectual disabilities. Together, these findings and the additional questions they posed helped set the stage for the MN-ADDM project.

Better access to services, earlier detection

Researchers expect to release the initial results from the MN-ADDM project in late Fall 2017, with updated data to follow every two years. The CDC will include this data as part of its biennial ADDM report, which provides a national overview of autism prevalence between states and can help inform public health decisions made by policymakers and CDC experts.

Consistent methodology between the ADDM sites means that experts can use the most recent data to compare trends between states — for example, the 2016 CDC report shows only 1 in 92 Wisconsin 8-year-olds are on the autism spectrum, while 1 in 66 Arizonans are. The combined data from ADDM sites will help researchers across the country pinpoint prevalence trends and inform discussions on possible causes of autism and work to understand what’s behind an increase in autism diagnoses.

Closer to home, researchers hope the data can shed light on a wide range of questions relevant to Hennepin and Ramsey counties. The study will reveal whether the earlier study’s trend of higher autism prevalence in Somali and white children still applies to the wider scope of the two-county area. It will also include the Hmong demographic, which had too little data to be represented in the previous study. Overall, the data will help promote autism awareness, increase understanding of rates of autism across diverse communities, develop new state policies and coordinate services for those with autism.

The results will also help with the University’s outreach to communities across the metropolitan area, informing community-facing efforts like the Minnesota Act Early, a statewide campaign that reaches out to families, communities and organizations to promote early screening for and identification of autism and other developmental delays. The findings will also help improve the U’s Leadership Education in Neurodevelopmental and Related Disabilities (LEND) program, a transdisciplinary collaboration that promotes training for students and community members that engage and support children with autism spectrum disorder and other neurodevelopmental disabilities.

Understanding more about autism’s prevalence in different communities could help experts make an important stride for public health: lowering the average age of autism diagnosis. While the 2013 study found the average age of diagnosis in Minneapolis is 5 years, experts can reliably diagnose autism as early as age 2.  The earlier the diagnosis, the sooner children can receive the valuable intervention services they need to support healthy development and improved life outcomes.

“Ultimately, this project will help us to better understand autism prevalence and how to better serve children and families in our state,” Hall-Lande said. “We have the power to change a child’s life through early identification and early intervention.”