Many people, including US Health and Human Services Secretary Robert F. Kennedy Jr., say that autism rates have reached epidemic proportions. But while the prevalence of autism spectrum disorder (ASD) has risen since the 1980s, experts say that greater awareness and improved testing are behind the increase in diagnoses.
Indeed, a study published this week in JAMA Pediatrics examining birth cohorts finds that the number of children with ASD has held steady.
“[The] prevalence of ASD remained stable across consecutive birth cohorts,” wrote the authors, led by researchers at the University of Texas at Austin. “This pattern suggests improved detection rather than increased ASD occurrence and does not support an ASD epidemic.”
Incidence, prevalence stable over 7 years
The scientists looked at all South Korean children from 12 consecutive birth cohorts born from 1998 to 2010 and aged 7 from 2005 to 2017 to understand the long-term incidence and prevalence of ASD.
This group included more than 62,000 children from Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). Of this group, 2,077 kids had a positive screening exam and were invited for diagnostic testing, 881 of whom underwent assessments. In total, 447 children ultimately received an ASD diagnosis.
This pattern suggests improved detection rather than increased ASD occurrence and does not support an ASD epidemic.
Both the cumulative incidence and prevalence of ASD remained constant over seven years, ranging from 1.9% to 3.2% for incidence and 2.0% to 3.4% for prevalence, with no statistically significant increase or decrease. The US Centers for Disease Control and Prevention says the prevalence of ASD is 3.2% in US 8-year-olds, making the study results consistent with current rates.
“The findings of this cohort study indicate 7-year cumulative incidence and age-7 prevalence of ASD remained stable across 12 consecutive birth cohorts, contradicting claims of an autism epidemic,” the authors wrote.