Prevalence estimates indicate racial bias

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Estimates for autism’s prevalence in three U.S. states reveal significant inequalities in how children of different races and ethnicities are counted and assessed, according to two new studies.

In Wisconsin and Colorado, black and Hispanic children are more likely than white children to lack health or residency records, which excludes them from prevalence analyses, suggests a study published in Autism1. And in New Jersey, black children are half as likely as white children to receive an autism assessment by age 3, according to unpublished work presented earlier this month at a conference.

The data for both studies come from the Autism and Developmental Disabilities Monitoring Network, a nationwide surveillance program run by the U.S. Centers for Disease Control and Prevention.

The program has consistently found racial and ethnic disparities in autism prevalence. Its researchers reported last year, for instance, that fewer black children than white children have been diagnosed with autism in three states, including Wisconsin, and fewer Hispanic children have been diagnosed in seven states, including Colorado2.

In the new study, Durkin and her colleagues found the reasons for these discrepancies in state records. The study exposes systemic biases in children’s access to expert care, says Sydney Pettygrove, assistant professor of epidemiology and biostatistics at the University of Arizona in Tucson, who was not involved in either study. “The way our whole system sees and treats people is based on their ethnic group,” she says.

Durkin and her colleagues revisited the records that clinical reviewers had used to gauge autism prevalence in Wisconsin and Colorado.

The reviewers generally categorize children as ‘autistic,’ ‘not autistic’ or ‘suspected case’ based on the children’s school and healthcare records. Children without healthcare records are more likely to fall into the suspected category than those with complete information, the study found. And the ultimate estimates for prevalence do not include these suspected cases.

Among children flagged for autism, 45 percent of black children and 23 percent of Hispanic children lack healthcare records, compared with 11 percent of white children. And these black and Hispanic children are significantly more likely than their white counterparts to be classified as a ‘suspected’ rather than ‘confirmed’ case of autism.

When the researchers added back a subset of suspected cases to their calculations for prevalence, the disparity between black and white children disappeared. However, the difference between Hispanic and white children remained.

Children with patchy residency records are also liable to be overlooked, Durkin says. For instance, any child who is missing proof of residency for the year she turned 8 is automatically excluded from the analysis. “It’s a very stringent requirement,” Durkin says.

This problem particularly affects Hispanic children: 44 percent of the children flagged as having autism but missing residency information are Hispanic; by comparison, Hispanic people constitute 19 percent of total autism cases in Wisconsin and Colorado.

The unpublished study adds to this picture of racial inequalities. It found that black children in New Jersey are half as likely as white children to be evaluated for autism by age 3. This assessment gap exists despite the prevalence of autism being about the same across black, Hispanic and white children in the state. And the disparity held even when the researchers controlled for sex, level of autism severity and socioeconomic status.

The discrepancy is important because children evaluated later often end up waiting longer to receive treatment, and timely treatment is among the best indicators of a good outcome for autistic children.

The large gap surprised the study’s lead investigator, given New Jersey’s reputation for equitable delivery of clinical and educational services. “I still don’t understand it,” says Walter Zahorodny, who directs the New Jersey autism study site at Rutgers New Jersey Medical School in Newark.

The difference between Hispanic and white children’s ages at early evaluation was not significant after the researchers corrected for socioeconomic status and other factors. Zahorodny’s team presented the findings at the 2019 meeting of the International Society for Autism Research in Montreal.

The new studies suggest that systemic biases affect both how researchers collect data to estimate prevalence and children’s access to services

I'm afraid the racial bias runs deeper than a lack of record keeping. Having worked in the school system for 15 years, I can tell you that the response to minority students' behaviors is much more likely to be passing them off as bad parenting, oppositional defiance, and/or work avoidance than the response to the behaviors of their white peers.

No doubt there are social factors that could result in underdiagnoses of minority individuals, but is there any evidence that autism would be expected to be evenly racially distributed? Many medical conditions are not.

Coincidentally, about 50-60 years ago (and before), in central-lower Michigan, cultural stigmatization of mental illness was so prevalent in the average white community that a common belief was that only the worst sort of person had mental problems -- the morally depraved -- and that kids who nowadays would be diagnosed with ADD, ADHD, a depressive disorder, or autism were lumped together as "ret*ds" and placed in "Special Ed" classrooms, where the teachers were more concerned with keeping the students quiet than with teaching anything beyond the basics.

If a kid acted out in a Special Ed class, he or she was sent to Highfields -- a juvenile detention facility.

If the kid was really disruptive, there was always the 8th floor of Sparrow hospital -- the psych ward -- or the Ionia State Hospital, where they never to be heard from again.