In honor of the anniversary of Autism Speaks’ founding on Feb 25, for the next 25 days we will be sharing stories about the many significant scientific advances that have occurred during our first five years together. Our 25th item, Autism Prevalence Reaches 1:110, is from Autism Speaks’ Top 10 Autism Research Events of 2009.
In 2009, two major studies using different research methodologies yielded strikingly similar and eye-opening results showing that ASD affects approximately 1% of children in the United States. Based on data collected just four years earlier, it was found that ASD affected 1 out of every 150 children in the U.S. This represents a 57% increase in ASD prevalence in a relatively short period of time. Both studies also found that ASD continues to be four times more common in boys than girls.
In the first study, published in Pediatrics, authors from the U.S. Department of Health and Human Services (HHS) and the Centers for Disease Control and Prevention (CDC) collected data through the National Survey of Children’s Health (NSCH) on parent-reported diagnosis of ASD. Among a nationally representative sample of 78,000 children aged 3 to 17 years, the investigators found that 1 in 91, or an estimated 673,000 children in the U.S. had an ASD. While concerns lingered over the parent-reported nature of the data, this large-scale study set the stage for another major publication on ASD prevalence with similar results.
In December researchers at the CDC released new prevalence data collected by the Autism and Developmental Disabilities Monitoring Network (ADDM), a series of surveillance sites throughout the U.S. that maintain medical and service records on children with autism. By abstracting data and subjecting those records to stringent clinical evaluation, the authors found that approximately 1 in 110 children, 1 in 70 boys, met the criteria for ASD. This 1 in 110 statistic, based on data collected in 2006, represents a 57% increase from the 1 in 150 statistic which was based on data collected by the ADDM network in 2002 using identical research methods to the current study.
In a year that was jam-packed with publications on autism epidemiology, a number of other studies sought to investigate the reasons for the dramatic increase witnessed in autism prevalence. Researchers from Columbia University reported that approximately 25% of the rise in autism caseload in California between 1992 and 2005 could be directly attributed to changes in diagnostic criteria that resulted in a shift from mental retardation diagnosis to autism diagnosis. Therefore, converging evidence from this study and others around the world suggests that while changes in diagnostic practice may account for a portion of the increase, they cannot alone explain the rise in autism prevalence, and other factors, including environmental factors, likely play a role. One environmental factor that continues to be implicated in the increase in autism prevalence is parental age. Researchers from the California Department of Public Health reported in 2009 that parental age and particularly maternal age is a significant risk factor for autism, with a 10-year increase in maternal age increasing the odds of having a child with autism by 38% and mothers over the age of 40 at highest risk.
The prevalence studies of 2009 helped shed additional light on the immense nature of the autism public health crisis. With 1% of the U.S. population affected by ASD, and emerging data suggesting that 1% of the global population may be affected by ASD, never has the need for funding to support research into the causes and treatments of ASD been greater. In addition, these findings call attention to the necessity for more accessible diagnostic and intervention services for the growing population of those affected. In the CDC’s ADDM report and a separate study published in the Journal of the American Academy of Child and Adolescent Psychiatry, it was reported that while we can now reliably diagnosis autism spectrum disorders at two years of age, children on average are still being diagnosed at close to 6 years of age. This means that there is a large gap between the time that children can effectively be diagnosed at age 2, and the time they are actually receiving a diagnosis – valuable time lost where early intervention services can dramatically improve outcomes.
Did you know?: Autism Speaks, in partnership with the CDC, developed the International Autism Epidemiology Network, a forum to facilitate collaboration and information sharing between autism experts around the globe. Launched at the International Meeting for Autism Research (IMFAR) in May of 2005, today the network supports over 100 participants from 30 countries and its activities have resulted in over $2.5 million in targeted international epidemiology research funding from Autism Speaks. This includes the launch of two RFAs in 2008 designed specifically to better understand global autism prevalence and risk factors – click here for more information on the funded grants.
This part 2 of a 2 part series is from Michael Rosanoff and Andy Shih, Ph.D. who both work in the Autism Speaks science department. This second post is from Andy Shih. Both guest bloggers bios are below the post.
The release of the latest prevalence data by the CDC last week was important in two ways. One, of course, is its implication for the role of environmental risk factors in autism. The other is how the finding enhances awareness and supports our call for more money for research.
The same can be said for our international epidemiology efforts. As part of our Global Autism Public Health initiative (GAPH), we have been funding and planning prevalence studies with our international partners and colleagues for the past several years. In South Korea, for instance, we are expecting the publication of the first ever prevalence estimate in early 2010. We also have prevalence studies in various stages of development in Albania, India, Ireland and Mexico. All these efforts involve members of our International Autism Epidemiology Network.
In addition to the contributions these studies can make to our understanding of autism, they will also help raise awareness and inform policy development in parts of the world where affected individuals and families struggle with severe stigma, and in many instances, little or no support and care. Another way to look at it is that when you conduct a prevalence study, you are basically asking members of the autism community to stand up and be counted. When that happens, especially if the number is anywhere close to the 1 percent figure we have here in the States, their plight and needs can no longer be ignored.
Andy Shih, Ph.D. is the Vice President of Scientific Affairs at Autism Speaks, where he oversees the etiology portfolio, which includes research in genetics, environmental sciences, and epidemiology. He was responsible for the formation and development of Autism Speaks sponsored international autism research collaborations, the Autism Genome Project and the Baby Siblings Research Consortium. Andy also leads Autism Speaks’ international scientific development efforts, such as the Global Autism Public Health Initiative (GAPH). Andy joined the National Alliance for Autism Research (NAAR) in 2002.
Prior to joining NAAR, Andy had served as an industry consultant and was a member of the faculty at Yeshiva University and New York University Medical Center. He earned his Ph.D. in cellular and molecular biology from New York University Medical Center.
Andy’s research background includes published studies in gene identification and characterization, virus-cell interaction, and cell-cycle regulation. He was instrumental in the cloning of a family of small GTPases involved in cell-cycle control and nuclear transport, and holds three patents on nucleic acids-based diagnostics and therapeutics. Andy is a resident of Queens, where he lives with his wife, daughter and son.
Michael Rosanoff, MPH, is a member of Autism Speaks etiology team and manages the organization’s epidemiology and public heath research grants. Since joining the organization in 2007, Michael has been the staff lead in overseeing the International Autism Epidemiology Network (IAEN) and is part of the development team for the Global Autism Public Health Initiative (GAPH). He is also a member of Autism Speaks Grants Division, helping oversee the administration of the organization’s grant-making process for research.
Prior to joining Autism Speaks, Michael conducted independent research at the Gertrude H. Sergievsky Center, a clinical, epidemiological and genetic research center at Columbia University Medical Center focused on developmental disorders of the nervous system. His research background is in genetic and psychiatric epidemiology as well as behavioral neuroscience and neuroimmunology, with publications in the fields of epilepsy and depression. Michael earned his Master of Public Health (MPH) in epidemiology from Columbia University’s Mailman School of Public Health and resides in N.J.