A release from the Centers for Disease Control and Prevention (emphasis added below):
The Centers for Disease Control and Prevention (CDC) estimates that 1 in 68 children (or 14.7 per 1,000 eight-year-olds) in multiple communities in the United States has been identified with autism spectrum disorder (ASD). This new estimate is roughly 30 percent higher than previous estimates reported in 2012 of 1 in 88 children (11.3 per 1,000 eight year olds) being identified with an autism spectrum disorder. The number of children identified with ASD ranged from 1 in 175 children in Alabama to 1 in 45 children in New Jersey.
The surveillance summary report, “Prevalence of Autism Spectrum Disorder among Children Aged 8 Years – Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2010,” was published today in the CDC’s Morbidity and Mortality Weekly Report. Researchers reviewed records from community sources that educate, diagnose, treat and/or provide services to children with developmental disabilities. The criteria used to diagnose ASDs and the methods used to collect data have not changed.
The data continue to show that ASD is almost five times more common among boys than girls: 1 in 42 boys versus 1 in 189 girls. White children are more likely to be identified as having ASD than are black or Hispanic children.
Levels of intellectual ability vary greatly among children with autism, ranging from severe intellectual challenges to average or above average intellectual ability. The study found that almost half of children identified with ASD have average or above average intellectual ability (an IQ above 85) compared to a third of children a decade ago.
“Community leaders, health professionals, educators and childcare providers should use these data to ensure children with ASD are identified as early as possible and connected to the services they need,” said Coleen Boyle, Ph.D., M.S. hyg., director of CDC’s National Center on Birth Defects and Developmental Disabilities.
The report also shows most children with ASD are diagnosed after age 4, even though ASD can be diagnosed as early as age 2. Healthy People 2020, the nation’s 10-year health objectives, strives to increase the proportion of young children with an autism spectrum disorder (ASD) and other developmental delays who are screened, evaluated, and enrolled in early intervention services in a timely manner.
The news media will focus on the increased prevalence figure and may overlook this passage:
The global prevalence of autism has increased twentyfold to thirtyfold since the earliest epidemiologic studies were conducted in the late 1960s and early 1970s. At that time, prevalence estimates from European studies were one in 2,500 children in the population (2), and by the 2000s prevalence estimates from large surveys were 1%–2% of all children (3–5). Although the underlying reasons for the apparent prevalence changes are difficult to study empirically, select studies suggest that much of the recent prevalence increase is likely attributable to extrinsic factors such as improved awareness and recognition and changes in diagnostic practice or service availability (5,6).
5. Blumberg SJ, Bramlett MD, Kogan MD, et al. Changes in prevalence of parent-reported autism spectrum disorder in school-aged U.S. children: 2007 to 2011–2012. Natl Health Stat Rep 2013;65:1–11.
6. Schieve LA, Rice C, Devine O, et al. Have secular changes in perinatal risk factors contributed to the recent autism prevalence increase? Development and application of a mathematical assessment model. Ann Epidemiol 2011;21:930–45.
