Disparities in autism diagnosis may harm minority groups

Clinicians are underdiagnosing autism in children from low-income families and minority groups — setting back their potential to benefit from therapy. That’s the upshot of two studies presented this week at the 2016 International Meeting for Autism Research in Baltimore.

In one of the studies, researchers showed that a disparity in autism diagnosis in the United States favoring white children from high-income families remained stable from 2002 to 2010, despite increasing awareness of the condition.

Analyzing data collected in 2010 by the U.S. Centers for Disease Control and Prevention (CDC), they found that children from high-income families are roughly 81 percent more likely to receive an autism diagnosis than those from low-income families. This number has not changed significantly from the data collected in 2002 or in 2004.

Since 2004, awareness of autism has increased, and in 2006, the American Academy of Pediatrics recommended that doctors conduct routine screening for autism. Still, the disparity in autism diagnoses hasn’t improved, says Maureen Durkin, professor of population health sciences and pediatrics at the University of Wisconsin-Madison, who presented the findings yesterday. “We haven’t seen any evidence yet that the gap is closing.”

Although the results are discouraging, it is possible that the routine screening had not been in place long enough to have an effect on the 2010 data, Durkin says.

Diagnosis gap:

Black and Hispanic children are also less likely to get a diagnosis of autism than are white children, based on the 2010 data. This difference, too, can be largely explained by socio-economic status, says Durkin.

For example, black and white children from families of high socio-economic status — those who fall into the top one-third of income earners in the U.S. — have roughly equivalent rates of autism diagnosis. However, as a group, black children have a low rate of autism diagnoses because only 18 percent of black families are in this high-income category.

In one optimistic sign, the data suggest that for white children with autism, the impact of socio-economic status is starting to fade. Rates of autism in white children from low-, middle- and high- income families are more similar in 2010 than they were in 2002.

This is not the case for black and Hispanic children, but it offers hope that the rates may change as autism awareness increases. Alternatively, the findings might mean that some disparities in diagnosis stem from racial differences that are independent of socio-economic status.

Whatever the reason, delayed diagnosis in black children may cause them to fare worse than white children with the condition. In work presented Thursday, another group of researchers found that black children who were diagnosed at a clinical center for autism tend to have lower verbal ability than white children do, and are more likely to have intellectual disability.

The findings highlight how little is known about racial differences in autism, says Celine Saulnier, clinical director for research at the Marcus Autism Center in Atlanta, who presented the work.

Saulnier says that she had diagnosed thousands of children with autism in northeastern states of the U.S., but didn’t realize that this was a uniquely white, middle-to-upper-class type of autism until she moved to the Marcus Autism Center five years ago, where she sees a more diverse group of children. “I really had a lot to learn,” she says.

Language barriers:

Her team looked at detailed clinical data collected for 95 black children and 60 white children diagnosed at centers for autism research in either Los Angeles or Atlanta.

As a group, the black children have verbal intelligence scores roughly 20 points lower than the white children do. And 53 of the 95 black children have intelligence quotients (IQ) below 70, an indicator of intellectual disability, compared with 13 of the 60 white children.

The most “sobering finding,” says Saulnier, is that even among children with an IQ above 70, black children have poorer language and communication skills than do white children.

These differences might stem from the fact that black children tend to be diagnosed later than white children, and so do not receive behavioral treatments early enough to help them, says Saulnier.

“I think if we start early, we can close these gaps in language functioning before these children even reach verbal age,” she says. “Then, hopefully, we can change these disparities in the future.”

It is unclear why researchers are finding these differences across racial groups, says Mayada Elsabbagh, assistant professor of psychiatry at McGill university in Montreal, who was not involved in either new study.

“Yes, you might find an increase in black children on a certain measure, but that tells me very very little about where that’s coming from,” she says. “It could be the child, it could be the person rating them, or it could be the tool that you’re using.”

Now that researchers are aware of these trends in autism, they need to design studies to answer these questions, Elsabbagh says. “We need to have better questions, not just look for patterns or differences in the data.”

For more reports from the 2016 International Meeting for Autism Research, please click here.