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About 1 in 59 children in the United States has autism, according to data released today by the U.S. Centers for Disease Control and Prevention (CDC). Four times as many boys as girls have the condition, according to the report1.
The data are based on a 2014 survey of 325,483 children across 11 states. The data were collected by the CDC’s Autism and Developmental Disabilities Monitoring Network (ADDM).
These numbers show an increase of nearly 16 percent from the previous prevalence of 1 in 68 children. That estimate was based on data collected in 2012 and had a gender ratio of 4.5 to 1.
The trend from that analysis and another one in 2010 had suggested that autism prevalence in the U.S. was leveling off. Another CDC study published earlier this year also suggested that autism rates are no longer increasing.
The new findings buck this trend. But they do not necessarily mean the actual number of children with autism in the U.S. is rising, says Catherine Rice, director of the Emory Autism Center in Atlanta and principal investigator for the ADDM from 2001 to 2010.
“The current ADDM report seems to indicate that awareness of [autism] characteristics is broadening and this contributes to increases in [autism] prevalence overall,” Rice says.
For example, autism prevalence is consistently higher in white children than in black or Hispanic children—a pattern researchers attribute to disparities in access to medical care. This difference has been trending downward since 2002.
The 2012 analysis identified 20 percent more white children with autism than black children and 50 percent more than Hispanic children. In the new analysis, researchers identified 7 percent more white children with autism than black children, and 22 percent more than Hispanic children.
This suggests that the rise in prevalence may be the result, in part, of improved services for children who were previously missed.
“We have no reason to think there’s some biologic basis for a difference in [autism] prevalence among these populations,” says Deborah Christensen, team lead for surveillance in the CDC’s developmental disabilities branch. “So when we see those differences narrow, that is encouraging to us.”
The new survey focused on 8-year-olds, as most children are likely to have had a medical or school evaluation by that age.
Expert reviewers in the ADDM look for signs of autism in the medical records of children living in select counties and states across the U.S.
The reviewers may include children who show signs of autism, even if they do not have an official diagnosis. And they may choose to exclude children who are diagnosed with autism if their features do not meet criteria for autism as outlined in the “Diagnostic and Statistical Manual of Mental Disorders” (DSM).
The CDC report shows dramatic differences in autism prevalence among states. The highest prevalence is 2.93 percent in New Jersey, whereas the lowest is 1.31 percent in Arkansas.
This divergence may reflect real differences in the number of children who have autism.
Alternatively, it may reflect a disparity in access to healthcare and in autism awareness among different counties, says Radley Sheldrick, associate professor of health law, policy and management at Boston University. States with a lower prevalence may have more children with unrecognized autism, for example.
“Symptoms of [autism] are more likely to be documented in medical and educational records in some states than in others, and this affects results,” he says.
For 10 states, the reviewers looked at education records for evidence of special needs or services. Having access to this information may boost states’ prevalence, says Christensen.
The reviewers had access to education records in one state—Wisconsin—for the first time, and to more records for Colorado than they had previously. These two states showed the highest increase in prevalence: The reported prevalence in Wisconsin rose by 31 percent between 2012 and 2014, and the prevalence in Colorado rose by 29 percent.
What’s more, all of the states with robust special education records show prevalence estimates over the national average.
Despite the rising awareness, only 42 percent of children with autism had a diagnostic evaluation by age 3, even though about 85 percent showed some signs of the condition by that time. This discrepancy is of concern, says Rice.
“It is way past time of accepting the long wait from concern to evaluation to services as an okay standard in the United States,” she says.
The average age for a diagnostic evaluation has stayed relatively consistent over the years. However, states may be able to take steps to improve this. For example, for more than a decade, North Carolina has implemented state-wide initiatives to improve early screening for developmental delays. Perhaps as a result, 66 percent of children identified with autism in this state had received a diagnostic evaluation before age 3.
Local factors can have a big impact on prevalence. Sheldrick and his colleagues have found that the disparity in prevalence among U.S. states has steadily increased between 2000 and 20122.
For example, data for two of the states with the highest prevalence—Maryland and Minnesota—come from small sampling areas clustered near a diagnostic center. And New Jersey is well known for providing strong access to medical and special education services. New Jersey also does not show significant disparities in prevalence among ethnic groups, suggesting that as autism identification improves, these disparities disappear.
“People think of [national prevalence] as true prevalence, and I think we need to be careful of that interpretation,” Sheldrick says. “If New Jersey represents the true rate, that’s a lot higher than [the average], and that has real implications.”
The variation across states also reveals how dependent the CDC estimate is on the sites that provide the data, says Eric Fombonne, professor of psychiatry at Oregon Health and Science University in Portland.
“Where services are located and how people access services in particular states varies enormously from site to site, and that affects tremendously the prevalence estimate that they have,” Fombonne says. “It shows very clearly that the methods are not as robust as you would like them to be.”
The new report looks at prevalence for a subset of the participants, using diagnostic criteria outlined in the DSM-5, the current version of the DSM, released in 2013. The criteria for autism in the DSM-5 may be more stringent than those in the DSM-IV. This suggested that basing the prevalence on children who met the DSM-5 criteria would lower prevalence estimates.
In the new study, the ADDM researchers tried to gauge the impact of switching to the new manual. They found that using the DSM-5 criteria yields 4 percent fewer cases of autism than with the DSM-IV criteria—a difference they say is negligible.
However, any child who had an autism diagnosis with DSM-IV criteria is automatically given an autism diagnosis with the DSM-5. This rule artificially inflates the number of DSM-5 diagnoses, says Fombonne: Roughly 15 percent of children who received a DSM-5 diagnosis did not have sufficient behaviors to warrant this status based on DSM-5 criteria alone.
The comparison is “completely bogus because they are comparing two things, which are not independent; they are comparing a definition that includes the other one,” Fombonne says.
The ADDM plans to rely only on DSM-5 criteria when they report prevalence for 2016. That analysis may reveal whether switching to the manual lowers prevalence, says Christensen.
The new survey also collected data on 4-year-old children, which the CDC plans to publish separately. This analysis may clarify the average age at which children with autism are identified.
Baio J.B. et al. MMWR Surveill. Summ. 67, 1-23 (2018) Full text
Sheldrick R.C. and A.S. Carter J. Autism Dev. Disord. Epub ahead of print (2018) PubMed
After Keith Beck died of bile duct cancer last year, family members said more than 900 people showed up to pay respects to the popular athletic director at the University of Findlay in northwestern Ohio.
Many were former students who recalled acts of kindness during Beck’s nearly 30-year career: given to a kid who was broke, textbooks bought for a student whose parents were going through bankruptcy, a spot cleared to sleep on Beck’s living room floor.
But few knew about Beck’s final gesture of generosity. The 59-year-old had agreed to a “rapid autopsy,” a procedure conducted within hours of his death on March 28, 2017, so that scientists could learn as much as possible from the cancer that killed him.
“He was 100 percent for it,” recalled his ex-wife, Nancy Beck, 63, who cared for Beck at the end of his life. “It wasn’t the easiest thing to do, but it was important.”
Beck donated his body to a rapid-autopsy research study at the Ohio State University, part of a small but growing effort by more than a dozen medical centers nationwide. The idea is to obtain tumor tissue immediately after death—before it has a chance to degrade. Scientists say such samples are the key to understanding the genetics of cancers that spread through the body, thwarting efforts to cure them.
“People are recognizing that cancer is more heterogeneous than we realize,” said Dr. Sameek Roychowdhury, a medical scientist at OSU’s Comprehensive Cancer Center. “Different parts of your body may have different cancer cells, even though they originated from the same cancer.”
In Beck’s case, results from the rapid autopsy showed he had developed a mutation that caused the experimental drug he was taking, known as an FGFR inhibitor, to stop working. Roychowdhury and colleagues plan to report on Beck’s case in an upcoming paper.
“This is helping us shape how we develop this new drug,” Roychowdhury said. “How can we make a better drug? Or can we make a better drug combination?”
Rapid-autopsy technology has been available for decades. Researchers at the University of Washington in Seattle have been using the technique to study prostate cancer since 1991. Scientists at the University of Nebraska Medical Center launched a now-robust program in 2000.
But only in recent years have more hospitals been launching and expanding programs, said Dr. Jody Hooper, director of the Legacy Gift Rapid Autopsy Program at Johns Hopkins Medicine in Baltimore. At last count, there were 14 similar programs in the U.S.
Funding for them varies, Hooper said, but typically they’re supported by a mix of cancer program resources, grants and researcher fees.
Scientists recognize the value of examining tissue from multiple sites soon after death and obtaining larger samples than they could while a patient was living. Cancer cells can be retrieved during such autopsies and kept alive, allowing researchers to experiment with ways to treat—or kill—them.
“It’s the power of sampling over the entire body at the same time,” said Hooper, who conducts about one rapid autopsy a month, often providing tissue for up to a half-dozen researchers interested in different questions.
Most programs focus on cancer, but efforts are underway to expand the practice, possibly to shed light on virus reservoirs in HIV patients, for instance.
Speed is essential to preserve RNA and DNA, the building blocks of cells, which can degrade quickly after death. It’s best to obtain specimens of living cells within six hours of death and other tissue within 12 hours, Hooper said.
The need for speed is also what makes such autopsies challenging. Families must consent to the procedure, often while freshly grieving their loved one’s death. And the logistics surrounding retrieving a body, conducting an autopsy and then returning the body for a funeral are often complicated. Traffic is unpredictable and “one time, there was a blizzard,” Hooper said.
Roychowdhury said he and one of his clinical fellows are on call at all times.
“The patients have our cellphone numbers, as well as the next of kin,” he said.
Broaching the subject with patients and families requires tact and compassion. Most patients are enrolled in clinical trials and learn about the autopsies from their doctors or pathologists like Hooper. Many are willing, even eager, to cooperate, she said.
“These are mostly patients with metastatic cancer,” she said. “They’ve made their peace with the outcome long before.”
For some, the rapid autopsy is simply the final phase of the clinical trial.
“They want to do something not only for themselves, but also to help others,” Roychowdhury said.
That’s how Linda Boyed, 52, of Lewis Center, Ohio, sees it. Like Beck, she has bile duct cancer and is enrolled in a trial to treat it. The drugs are working now, but Boyed said she has agreed to a rapid autopsy after death so scientists can learn from her when they’re no longer effective.
“I have a strong Christian faith,” she said. “I believe we’re put on this Earth to help each other.”
Because the rapid autopsies are paid through program funds and grants, there’s no cost to the families. Bodies are returned within a day and in a condition that doesn’t affect funeral plans.
“My emphasis is that it was all done with dignity and respect,” said Nancy Beck. “We felt honored to be able to do this.”
Performing the autopsy after treating a patient in life is an honor for doctors, too, Roychowdhury said.
“This was once a living, breathing person that came into my office every other week,” he said. “The thing I want to think about each day is that they’ve given so much so that others can benefit.
“Everyone has something to teach us after death.”