I have received many emails about yesterday’s post on the CDC autism prevalence study. I thought I would spend some time to briefly address 3 specific issues.

1. Prevalence Rates and Home Schooling.

I received a thoughtful email about the impact of home schooling on the CDC prevalence rate and autism research in general, given that many children with ASDs may be home schooled. Here is my response:

Regarding the CDC:
The prevalence was obtained from health records and, in some States, also educational records. States that used educational records had higher prevalence rates, and those records only included public school records. So theoretically, the prevalence would be even higher once home/private school cases are added. While education records may have included some children in private/home schools (many children in home school still receive special education services in some States and would therefore be identified by the CDC teams), many cases are likely being missed.

Interestingly however, the new CDC numbers are in line with the national autism prevalence study published in Pediatrics. This study was not based on educational or health records reviews, but instead it was based on detailed phone screenings of a representative sample of US families. Both of these studies however, would miss some children with ASD that are undiagnosed (and maybe home schooled) due to limited contact with health workers (pediatricians, etc). These children would not have any records showing that they have ASD symptoms and these parents would also respond ‘no’ to the basic phone screening question “have your child ever been diagnosed with an autism spectrum disorder?”

Regarding Research in General:
Fortunately, most research on autism is not conducted via the school systems. Most research is conducted at medical and university centers with families recruited from the community. In my neuropsychology assessment experience, I would say that at least 30% of the ASD kids we see are home schooled, and many of these children are active participants in our research programs. So the news is a bit better for general research, in that it is unlikely that home schooled kids are underrepresented in those studies.

2. Vaccines.

I really dislike writing anything about vaccines, mostly because regardless of how factual I aimed to be, any mention of vaccines is usually followed by a dozen of  ’friendly’ emails. But I’ve received several emails asking how the CDC numbers affect the vaccine theory. The CDC study does not address this issue at all, and the data say little about this theory. However, some reasonable conclusions can be made.

- If the increases in diagnoses among 8 year olds from 2002 to 2006 are due to real increases in true prevalence


- If vaccines play a role in the incidence of autism

- Then a 50% increase in the prevalence during the 4 year period should be accompanied by a noticeable change in vaccination practices during key years.

Specifically, the 2002 CDC  study was based on children born in 1994 and the new CDC study was done with children born in 1998.  Thus, given the striking increases in prevalence rates among the 1998 children, you would expect that compared to those born in 1994, children born in 1998 received higher vaccination dosages, received more harmful dosages, or simply were vaccinated at a higher rate. I have some data on vaccination rates:

I took a look at the CDC vaccination rates for MMR for those born in 1994 and 1998 by the time they were 2 years of age. You can take a look at the data here. The National vaccination rate for MMR for those born in 1994 was 90%. For those born in 1998, the vaccination rate was also 90%. For the states included in the CDC autism study, the vaccination rate for those born in 1994 was 90% and for those born in 1998 was also 90%. At the State and National level, there were no changes in vaccination rates for kids born in 1994 and 1998 that could help explain the 50% jump in autism prevalence.

12/28/09 UPDATE: Please note that in the paragraphs above I presented a simple logical argument for the vaccines debate. If vaccines played a role in the 1994 to 1998 autism rate change, then there must be a change in vaccination practices between 1994 and 1998-2000. Potential changes may have involved higher vaccination rates, changes in vaccine cocktails or contents, changes in schedules, etc etc. I then provided data for vaccination rates for one single vaccine as an example: MMR. Clearly such data are very limited and does not cover all possible changes that may have taken place during that time.

3. What’s up with Missouri?

Missouri had the highest autism rates of all states assessed (albeit it was a tie with Arizona in many measures), with rates that were often more than twice that of other States. One of my readers asked whether this was due to demographic differences in the target counties in Missouri. For example, is it possible that the data from Missouri came mostly from urban St Louis with a higher proportion of ethnic minorities or lower SES families? The data does not seem to support this theory. The Missouri sample was close to 70% white, and other States with significantly higher % of ethnic minorities in urban settings had significantly lower autism rates (e.g., Colorado – all from metro Denver with only 55% white; Florida – all from Miami with only 23% white; Georgia – all from metro Atlanta with only 38% white). We do not know why the high prevalence of autism in Missouri and Arizona, but it is very unlikely that it is due to demographic differences between these States and the other States included in the study.

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9 Responses to More thoughts on the CDC autism prevalence study: vaccines, home schools, and why Missouri?

  1. MG in NYC says:


    Again, the vaccination rates and the strawman of MMR is silly, regardless of what the anti-vaxers say about it. The correct structural model about vaccines and their relationship to autism has 3 possibilities: autism caused by overall toxicity, autism caused by autoimmune disturbances due to so many vaccines, or both. In either case, the vaccination rate of just MMR is a weak dependent variable a priori. We know this because the MMR vaccine or it equivalent has been around for a very long time, certainly longer than the rise of autism in the last 15 years. Thus, the right model is one that looks at the relationship of the # of innoculations at the various early stages of infancy. For example, if kids are getting a total of 30 shots by 24 months instead of 8 just 10 years ago, that would explain a lot. The CDC surely has this data, so why don’t they just look into it? That’s where the politics gets nasty. Meanwhile the epidemic continues.

  2. Dad Fourkids says:

    You are using a very narrow focus in your question of whether the increase in prevalance between the 1994 and 1998 birth cohorts could be attributed to vaccinations. Specifically, you have only mentioned 1 of the shots infants receive (the MMR), when there are many other given as well. The decade of the 90′s saw several changes to the schedule, including the push for a birth dose of Hep B, an addition of a fifth DTaP and the addition of a third IPV, all of which contained thimerosal. We also saw the addition of Prevnar and Varicella vaccines. So to look at 1 single shot and rest the case on there being approximately 90% coverage for both cohorts makes for a very weak argument.

    So in order to use the prevalance estimates from these two stdies to exxonerate vaccinations from the situation, it is absolutely necessary to not simply llok at a single shot these kids received as toddlers. You need to examine their medical files and carefully tally exactly what shots they received, when these were given, in what combinations, whether the child had a known contra-indicator which was ignored, whether the child received their shots when they were “under the weather” (something which has certainly become common place with our assembly-line pediatri practices of the last two decades), whether their is a clustering of subjects by any particular vaccine lots, whether there were any reformulations or other cahnges to any of the vaccines given around that time, etc.

    And this has not been done, so the question remains at this point up in the air.

    Meanwhile, here are a couple of studies, one clinical, one population to peruse at your leisure:



    • Dear DadFourkids, You are correct. In my post I mentioned several domains that would need to be explored when examining vaccination changes from 1994 and 2000, with overall vaccination rates being only one domain. Within this, I only provided data for the MMR vaccine, which is also limited and narrow, as there may be changes in rates among other vaccines or combinations of vaccines. I used MMR as an example as it has been one of the most commonly discussed vaccines in this debate. Thanks, Nestor.

  3. [...] do not link blogs as they are very subjective, but the point raised in this piece was interesting: More thoughts on the CDC autism prevalence study: vaccines, home schools, and why Missouri? – Child … As someone who works in the field of child health and has seen up close the devastation that [...]

  4. RAJ says:

    St. Louis is where John Costantino practices. He heads the Washington University autism research unit.


    He has close ties with the public school system in St. Louis and uses volunteers from the St. Louis school system for his research into autism. His concept of autism extends very broadly and includes people with any social anxiety as being on the spectrum.

    As a member of the APA working group on the pervasive developmental disorders he is recommending the scrapping of the three categories of PDD (Autistic Disorder, PDD/NOS, Asperger Syndrome). It would be replaced by a degree of severity ranging from profoundly handicapped to normal people with social anxiety (Normal variation PDD).

    It should be no surprise that St. Louis would have extraordinary high rates of ‘autism’ since Professor Costantino is an expert on ‘autism’ who who frequently consults with the school district including child study teams and ‘explains’ what ‘autism’ is, or at least his very broad view definition.

    These are ‘community diagnosted’ children with all sorts of diagnostic substitution taking place.

    Here is a list of studies published by Costantino and others trying to be all inclusive of a new definition of ‘Autism’, not as a disabling neuroligical disorder but rather a ‘trait’ condition:


    Plomins group in the UK also is a promoter of a wider prevelance of ASD as a trait condition have found that 5% of the general population possess ‘extreme autistic traits’:


    ‘Autism’ is a problem in search of a definition

  5. RAJ says:

    More on Constantino and St. Louis Missouri:

    As a member of the APA’s working group on autism he is very influential in defining diagnostic criteria for ASD. Here is a proposal which was published by the working group that has Constantino’s fingerprints written all over them:


    Here is another study he published and explains why he considers ADHD to a part of the ASD’s:


    The astonishing high rates of ‘autism’ in Missouri can be explained by Constantino’s influence with the St. Louis school district and his unusual concept of the definition of ‘Autism’.

  6. JulieL says:

    RAJ – Thanks for the information and Nestor thank you for your comments. I didn’t ask the question because I think SES status or cultural status have anything to do with autism prevalence, but rather I was curious because St. Louis city has been unfairly used in stats in all kinds of past reporting. I was curious to see if the population had been targeted by individuals diagnosing the group, again not that there was a true increase in population. I’ve read some view points that minorities are unfairly targeted, and was curious if these states lent to that theory. As Nestor pointed, they do not. But your point on Constantio is interesting.


  7. Ruth says:

    I really appreciate this analysis. I think that one of the other theories about autism and vaccines involves exposure to thimerosal, a mercury compound. Given that the CDC decided to phase out the use of thimerosal in 1999, if that were the trigger you might expect the prevalence to have gone down.

    On the other hand, I doubt that there is only one contributing factor to these numbers. I have a close relative who was recently diagnosed on the spectrum, but I think that 10 years ago, he would not have been diagnosed that way.

  8. Frank Martin DiMeglio says:

    The following “big picture” is absolutely essential to this entire discussion.

    The NUMEROUS vaccines are biologically active, and yet they are unnatural and foreign to the body. So when the body THEN reacts as if it is infected with disease (via immune responses/antibodies), is it not diseased/ill/damaged/infected to some extent? All of these NUMEROUS and altered/unnatural immune responses/vaccinations will eventually compromise our immune function. The answer is common sense and simple, and there is no way around this.

    Also consider: The vaccines (viruses and bacteria) are altered and unnatural; AND the disease/infection process is fundamentally different as well (via injection). This is all very significant, in keeping with everything else that can be/has been said.Understanding that autism meets the definition of a disintegration and contraction of being and experience is very helpful in understanding, preventing, and treating this disorder. The increasing numbers of vaccines and the rising rates of disorders involving mind/emotion/body are of very serious concern.

    The NUMEROUS vaccines are biologically active, and yet they are unnatural and foreign to the body. So when the body THEN reacts as if it is infected with disease (via immune responses/antibodies), is it not diseased/ill/damaged/infected to some extent? Also consider, all of these NUMEROUS and altered/unnatural immune responses/vaccinations will eventually compromise our immune function. Life is fragile, as it is delicately and precisely regulated and balanced. Artificially reconfigured/replaced sensory experience (including pollution, toxins, processed foods, television, vaccines, etc., etc.) is making us increasingly unconscious and reactive in various and unpredictable ways. We are becoming more inanimate.

    The reconfiguration, replacement, and loss of sensory experience (and feeling) includes toxins, vaccines, lack of exercise, processed foods, television, etc., etc. This is making us increasingly unconscious and reactive in various and unpredictable ways; and this involves sensory processing disorders as well.

    Autism is a disintegration, contraction, and detachment of being and experience (including consciousness). This also meets the definition/description of anxiety, depression, cancer, obesity, sleep disorders, and the experience of television. The NUMEROUS vaccines are biologically active, and yet they are unnatural and foreign to the body. So when the body THEN reacts as if it is infected with disease (via immune responses/antibodies), is it not diseased/ill/damaged/infected to some extent? Moreover, all of these NUMEROUS and altered/unnatural immune responses/vaccinations will eventually compromise our immune function, and worse. We are becoming more inanimate. The natural and integrated extensiveness of being and experience go hand in hand, as the disintegration, contraction, and detachment of being and experience go hand in hand as well. Author Frank Martin DiMeglio

    The great revelation of art (including music) is that the world requires and involves man; although science has been slow to recognize this; for the danger of technology is that it is creating a world of experience that is toxic and foreign to the self where man is neither truly involved nor required. By pervasively and fundamentally changing our various sensory experiences (including the range of feeling thereof), the self’s ability to represent and form a consistent, comprehensive, and relatively extensive approximation of sense is being compromised; whereby sense and feeling [increasingly] cannot be properly experienced, utilized, and understood as the expression and extension of the self’s desire; and it is not only our loss of language that we face. (Consciousness and language involve the ability to represent, form, and experience comprehensive approximations of experience in general; and this includes art and music as well.) The reconfiguration (i.e., disintegration, alteration, reduction, and/or replacement) of sensory experience in general (including range of feeling) is progressively involving a disintegration and contraction of being and experience (including thought). This is evident in (and includes) sleep disorders, depression, anxiety, autism, obesity, and the experience of television. (Clearly, obesity involves a disintegration, contraction, and detachment of being/experience; and it is associated with increased risk of death from all causes.)

    Moreover, there is no true difference between what is foreign/unnatural and toxic. Artificially reconfigured sensory experience (including pollution, processed foods, television, etc.) makes the self increasingly unconscious (and reactive) in unpredictable ways. The disintegration, alteration, reduction, and replacement of sensory experience and feeling involve the loss of the instincts; as the self is disconnected and detached from what is natural and truly sustaining. The disintegration and contraction (and this includes detachment) of being and experience go hand in hand. Being and experience are becoming excessively (and increasingly) unconscious and less animate. Finally, in reference to sleep disorders, it is important that dreams involve a fundamental integration and spreading of being and experience at the mid-range of feeling between thought and sense, in conjunction with the natural extensiveness and interactivity of being and experience.

    In both depression and anxiety, the emotional disintegration and contraction of being and experience involves increased feeling at the emotional center of the self. In anxiety, this is consistent with excessive concern, the reduction in the desirability of experience, emotional imbalance (or variability), bodily aches and pains (i.e., emotional disintegration), the mind “going blank”, panic attacks (involving a sort of generalized paralysis and loss of experience), etc. Comparatively (and similarly), in depression, there is a contraction, detachment, disintegration, and loss of being and experience that also involves a loss of emotion. The loss of desire in both depression and anxiety involves a significant reduction in the comprehensiveness and consistency of both intention and concern as they relate to experience in general; and this has the dream-like effect of reducing thought, emotion, and memory, including the desirability and totality of experience as well.

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