New Study in Journal Pediatrics is Misleading

Department of Education Data Inadequate to Determine Prevalence Over Time

AUTISM COMMUNITY CALLS NEW STUDY IN JOURNAL PEDIATRICS MISLEADING, DECLARES AUTISM EPIDEMIC REAL -- Department of Education Data Inadequate to Determine Prevalence Over Time

A study appearing in the April 2006 edition of Pediatrics titled “Diagnostic Substitution and Changing Autism Prevalence” is being questioned by the autism community. The report, authored by Dr. Paul Shattuck, uses US Department of Education data to support the hypothesis that real autism rates have not increased over the last two decades, and that reported increases are a function of reclassification of students from learning disabilities and mental retardation categories. This theory has been rejected in a number of scientific studies. The autism community would like to see scientific studies based on more valid databases in order to determine accurate prevalence trends.

The autism parent organizations including SafeMinds, National Autism Association, A-CHAMP, and Generation Rescue see this latest article as part of a phenomenon of epidemic denial that inhibits open scientific investigation of autism’s causes and blocks allocation of needed resources into autism. The groups note that the prevalence of autism now far exceeds other high profile disorders such as cerebral palsy, cystic fibrosis, and juvenile diabetes. They request that autism be recognized as a national emergency and that unbiased epidemiological studies be conducted that count both older and younger people with autism to see if the increases are real.

The paper’s use of Department of Education data to conclude no epidemic exists is troubling. The study author himself said that the data set is inconsistent and is subject to administrative and policy changes by the states. He notes that 28 of the 48 states included in the analysis do not support his theory of reclassification as a reason for autism increases. “Each state has its own rules and the autism rates by state vary greatly, so aggregating the state-level data to a US average is not good statistical practice,” explained Mark Blaxill of SafeMinds. “Other, more reliable data sets, like the California Department of Developmental Disabilities, do show a real increase in autism.”

Autism groups voiced support for the commentary by Dr. Craig Newschaffer that accompanies the Shattuck article in Pediatrics. This commentary makes a number of valid points regarding Dr. Shattuck’s approach and conclusions. The autism groups note that the hypothesis of reclassification, or “diagnostic substitution”, has been examined and rejected in several scientific papers as a likely major factor in reported autism increases. One study was authored by Dr. Newschaffer. A study by Robert Byrd and a study by Blaxill, Baskin and Spitzer have also ruled out diagnostic substitution.

For more information about the Shattuck study and autism prevalence please see the following links.

Pediatrics, Journal of the American Academy of Pediatrics April 2006 Article: The Contribution of Diagnostic Substitution to the Growing Administrative Prevalence of Autism in U.S. Special Education, Paul T. Shattuck, Ph.D.. The April 2006 issue of Pediatrics was not available online at time of publication, but should be available soon here.

Pediatrics, April 2006 Commentary: Investigating Diagnostic Substitution and Autism Prevalence Trends, Craig J. Newschaffer, Ph.D. The April 2006 issue of Pediatrics was not available online at time of publication, but should be available soon here.

Pediatrics, April 2006, Commentary: Diagnostic Substitution and the Changing Autism Prevalence, Paul T. Shattuck, Ph.D. The April 2006 issue of Pediatrics was not available online at time of publication, but should be available soon here.

Journal of Autism and Developmental Disorders April 2003, Commentary: Blaxill, Baskin & Spitzer on Croen et al (2002), The Changing Prevalence of Autism in California

Journal of Autism and Developmental Disorders April 2003, Response: A Response to Blaxill, Baskin & Spitzer on Croen et al (2002), The Changing Prevalence of Autism in California, Lisa A. Croen and Judith K. Gether

Public Health Reports, Nov-Dec 2004, What's Going On? The Question of Time Trends in Autism, Mark Blaxill, MBA

The Epidemic of Autism in California: Report to the Legislature of the Principal Findings from the Epidemiology of Autism in California: A Comprehensive Pilot Study, October 17, 2002, Robert S. Byrd, M.D., M.P.H., et al

Pediatrics, March 2005, National Autism Prevalence Trends from United States Special Education Data, Craig J. Newschaffer, Matthew D. Falb and James G. Gurney

Fighting Autism website for more information on Department of Education data.

UPI Autism Story Prompts Bill

WASHINGTON, March 30 (UPI) -- A U.S. congresswoman said Thursday she is drafting legislation to force the federal government to study the autism rate in never-vaccinated children -- a direct result, she said, of United Press International's reporting on the issue.

"Shouldn't someone in the medical community take a more scientific look at this?" Rep. Carolyn Maloney, D- N.Y., said at a briefing at the National Press Club. "Don't we deserve at least that much?"

Maloney cited reporting by UPI's Dan Olmsted in his Age of Autism column that found relatively few never- vaccinated children with autism. Olmsted looked for autistic children among unvaccinated Amish; in a subset of homeschooled children who are not vaccinated for religious reasons; and in a pediatric practice in Chicago with several thousand never- vaccinated children.

"Though admittedly unscientific, it is startling how dramatically lower the incidence of autism appears to be in these populations," Maloney said. "To date, no autism study of note has used a control group in which children who were never vaccinated were compared with children that did receive vaccinations containing thimerosal."

Most medical authorities -- including the Institute of Medicine, the Centers for Disease Control and Prevention and the American Academy of Pediatrics -- say there is no evidence linking vaccines and autism. But some parents and a minority of scientists suspect the culprit may be a mercury preservative called thimerosal that was used increasingly in vaccines beginning around 1990.

Thimerosal was phased out of routine childhood immunizations starting in 1999 but remains in most flu shots, which are now recommended by the CDC for pregnant women and for children 6 months to 5 years old.

"While I do not know if mercury causes autism, I can say definitely that parents deserve answers about this epidemic," Maloney said. "Right now, I believe there are still more questions than answers. We have the potential for a much more thorough and conclusive study of mercury and autism."

The proposed legislation would direct the secretary of health and human services to launch "a comprehensive study comparing total health outcomes, including risk of autism, in vaccinated populations in the United States with such outcomes in unvaccinated populations in the United States."

Maloney expects to introduce the bill in late April after allowing a period for comments and suggestions. It is posted at http://maloney.house.gov/documents/health/mercury/ 20060330DraftAutismBill.pdf

Federal health officials, including CDC Director Julie Gerberding, have said that such a study would be problematic because most American children have had at least some vaccinations; because autism diagnoses can be difficult to make and compare; and because never-vaccinated children in communities such as the Amish might have genetic differences that would invalidate such a study.

But at a news conference last summer Gerberding said such studies "could and should be done" if feasible.

Olmsted, who spoke at Thursday's briefing, said he believes that, besides the Amish, there are tens of thousands of never-vaccinated children who would be representative of the U.S. pediatric population.

Other speakers were David Kirby, author of "Evidence of Harm," a book about the thimerosal controversy from the perspective of parents of autistic children, and Lee Grossman, president of the Autism Society of America.

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Click here to see video interviews with Evidence of Harm author David Kirby and SafeMinds board members Lyn Redwood,Sallie Bernard, Mark Blaxill and Jim Moody.

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