Return to Main Menu

MUSC, CDC announce autism study results The Centers for Disease Control and Prevention (CDC) reported findings last week from the first and largest summary of prevalence data from multiple U.S. communities participating in an autism spectrum disorder (ASD) surveillance project. MUSC and Jane Charles, M.D., Developmental Pediatrics, were part of establishing this report. The CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network is the largest multi-site collaboration to monitor ASDs in the United States.   The results of this study showed an average of 6.7 children out of 1,000 had an ASD in the six communities assessed in 2000, and an average of 6.6 children out of 1,000 having an ASD in the 14 communities included in the 2002 study. All children in the studies were eight years old, because previous research has shown that most children with an ASD have been identified by this age for services.   “We’ve realized that it’s more common in South Carolina than we previously thought,” Charles said. “We actually fall in the middle when discussing states with low rates and others with higher rates. Now that we have some good information about the prevalence of ASD, we can start working toward studies that will investigate better treatment and screening methods. Having good estimates of ASD will also help us in planning and intervention efforts with school and other health disciplines so we can identify children with ASD earlier and get them the help they need.”   For decades, the best estimate for the prevalence of autism was four-to-five per 10,000 children. More recent studies from multiple countries using current diagnostic criteria conducted with different methods have indicated that there is a range of ASD prevalence between one in 500 children and one in 166 children. The CDC studies provide information on the occurrence of ASDs in 14 communities in the United States. “Our estimates are becoming better and more consistent, though we can’t yet tell if there is a true increase in ASDs or if the changes are the result of our better studies,” said Julie Gerberding, M.D., CDC director. “We do know, however, that these disorders are affecting too many children.”   Overall, the 2000 study found ASD rates ranged from one in 222 children to one in 101 8-year-old children in the six communities studied. The 2002 study found ASD rates ranging from one in 303 to one in 94 among 8-year-old children. The average finding of 6.6 and 6.7 per 1,000 8-year-olds translates to approximately one in 150 children in these communities. This is consistent with the upper end of prevalence estimates from previously published studies, with some of the communities having an estimate higher than those previously reported in U.S. studies. ASDs are developmental disabilities and are defined by considerable impairments in social interaction and communication and the presence of unusual behaviors and interests. They can be diagnosed as early as 18 months and last throughout a person’s life. ASDs include autistic disorder, pervasive developmental disorder - not otherwise specified (PDD-NOS, including atypical autism), and Asperger syndrome.   “It is extremely difficult to accurately estimate the number of children who have an ASD,” said Marshalyn Yeargin-Allsopp, M.D., chief of CDC’s autism program. “Medical records often do not provide such information, and identification is often made by schools or education specialists. It’s important to note that these studies don’t provide a national estimate, but that they do confirm that ASDs in the areas surveyed are more common in these communities studied than previously thought. We need to continue efforts to monitor the prevalence of ASDs and to improve our understanding of these disorders.”   In addition to trying to measure the number of children with an ASD, the studies also looked at when parents and others first noted signs of developmental concerns in their children. The 2000 and 2002 studies found 51 percent to 88 percent of children with ASDs had documented developmental concerns before the age of three. Half of the children were diagnosed with an ASD when they were between 4-and-one-half and 5-and-one-half-years-old. The most commonly documented concerns were in language development, followed by social development.   “We don’t know the causes of ASDs, but we do know that if we can identify autism and other developmental problems in children early, they can begin receiving appropriate interventions sooner,” said Yeargin-Allsopp. “It is important for parents, health care professionals and childcare providers to recognize developmental milestones such as smiling, pointing and waving bye-bye. It’s also important that health care professionals give children routine developmental and autism-specific screenings.”   While these studies did not investigate the causes of ASDs, CDC’s Centers for Autism and Development Disabilities Research and Epidemiology (CADDRE) Network is doing a multi-state study to help identify factors that may put children at risk for ASDs and other developmental disabilities.   The ADDM Network project is being conducted by CDC, University of Alabama at Birmingham, University of Arizona at Tucson, University of Arkansas, Colorado Department of Public Health and Environment, Johns Hopkins University, Washington University in St. Louis, University of North Carolina at Chapel Hill, University of Medicine and Dentistry of New Jersey in Newark, University of Pennsylvania School of Nursing, MUSC, University of Utah, Marshall University and the University of Wisconsin-Madison. Six sites participated in the 2000 project, and an additional eight were added for the 2002 project. MUSC also has been reselected as one of eight universities that will conduct the next phase of the ASD study.   To learn more about the results and autism, visit http://www.cdc.gov/ncbddd/autism/documents/AutismCommunityReport.pdf. Autism study and translational research    Thomas C. Hulsey, ScD., Pediatric Epidemiology director, expressed enthusiasm about Charles’ research and what it means for translational research at MUSC. As MUSC responds to a push from the federal government to grant more funding to those institutions who are able and willing to move research swiftly from the bench to the bedside, Hulsey sees studies like Charles’s CDC work as a great jumping off point.   “Recently the U.S. government announced it was earmarking additional new funds specifically to target the disorder (ASD),” Hulsey said. “The inclusion of translational research money would provide a greater opportunity to include information on mechanisms that might underlie the development of this disease. So we can go beyond observing, recording and documenting autism, to the inclusion of more mechanistic kinds of information that will help us further understand autism and related disorders even more than we do today. That could move a research study like the one Dr. Charles is conducting away from being traditionally public health, to also incorporate medical models of prevention and treatment.” Charles is widely respected as an expert on the screening, diagnosis and management of autism. She is, among other things, director of MUSC’s Carolina Autism Resource Evaluation, or CARE Center, one of three statewide that she helped to establish several years ago. At these clinics, Charles and her colleagues see children suspected to have ASD. The CARE clinic offers screening, diagnosis, assessment and management by a team composed of a developmental pediatrician, school psychologist and educational specialist.   “This team of physicians and specialists provides evaluations as well as management and education support,” Charles said. The team helps with developing treatment plans and effective learning teaching skills, works closely together to assess the child’s needs and skills, and recommends the best possible plan for service and training.   In response to concerns over a growing number of children with autism, Charles was one of two principal investigators for MUSC in the CDC study. According to Charles, the 10-year grant is largely translational.   “It’s really a public health project, a surveillance study to inform the public so they can use the information to come up with treatment strategy and intervention,” she said, “to inform the appropriate organizations so they can plan for adequate services, for instance, to help school districts plan teachers, and health care providers plan programs. The results of the study will help these groups predict how much money they’ll need for services, to plan for the financial impact. We’re translating information for the public. It’s research from the bedside to the community.”   While it’s clear that a larger number of kids with autism are being identified, and a larger number are receiving services from the public, the causes for these increases has not been proven.   “Current thinking is that it’s due to earlier identification and better awareness,” Charles said. “There’s also been change in diagnostic criteria—it’s become more relaxed, so it’s easier to get a diagnosis. There is also probably a true increase in the numbers, perhaps related to environmental triggers. The federal government is beginning to fund research to look at the effects of environmental toxins on child development.”     Friday, Feb. 16, 2007 Catalyst Online is published weekly, updated as needed and improved from time to time by the MUSC Office of Public Relations for the faculty, employees and students of the Medical University of South Carolina. Catalyst Online editor, Kim Draughn, can be reached at 792-4107 or by email, catalyst@musc.edu. Editorial copy can be submitted to Catalyst Online and to The Catalyst in print by fax, 792-6723, or by email to catalyst@musc.edu. To place an ad in The Catalyst hardcopy, call Island Publications at 849-1778, ext. 201.