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Professor Peter Bearman on vaccines and autism revisited

21 Apr

I’ve posted a few pieces on the work of Prof. Peter Bearman recently. I mentioned his work on vaccines and autism in one post but the lecture was not one that could be embedded and the part on vaccines is only a relatively short bit towards the end of the lecture.

So I took that section of the lecture out and put it on YouTube so I could embed it. This is discussing data from what I assume is an upcoming paper by Prof. Bearman’s group.

Prof. Bearman notes that vaccine refusal rates in California are higher in areas where autism organizations have a presence. However, vaccine refusal rates are *not* higher in areas with high autism prevalence.

In other words: autism isn’t scaring people away from vaccination. But, autism organizations are.

can be as much as 7 times higher if there are autism organizations in a given area. The baseline refusal rate in California is about 1.6% (in 2003). In other words, there are pockets of vaccine refusal of 10% or more in California, correlated with autism organization presence.

There are those who gloat about increasing fear of vaccines. It is too bad that time, money and effort didn’t go into something valuable to the autism communities. Let’s hope it doesn’t backfire on us in the form of infectious disease outbreaks blamed on the autism community.

Prof. Peter Bearman interviewd by Tom Insel

21 Apr

Prof. Peter Bearman is a sociologist at Columbia University who has undertaken a monumental task: figure out what is behind the increase in autism prevalence. He has chosen (at least so far) to work with California Department of Developmental Services data. This dataset is no where near the “gold standard of autism epidemiological data” that some have touted it to be. But it remains as one of, if not the best, dataset in the US.

I wrote about his most recent paper in Social influences on the rise in autism prevalence and Diagnostic change and the increased prevalence of autism.

Given the importance of this work, I thought it worthwhile to present this short interview of Prof. Bearman by the NIMH Director and IACC chair, Dr. Tom Insel. It is significantly shorter than the full lecture I linked to, and it is possible to embed it:

Prof. Bearman’s team is working on analyzing the California Department of Developmental Services (CDDS) dataset to see what trends can be identified.

Ascertainment, change in diagnostic criteria, increases in parental age, socio-demographic changes are factors in the increase in prevalence.

For example, in the past, it was wealthy families who were more likely to obtain an autism diagnosis for their child. Now that socio-economic divide is disappearing. This is a sign that ascertainment has been an effect.

Professor Bearman notes that some effects have been quantified:

25% of the increase is diagnostic change on the border between autism and mental retardation
16% of the increase is diagnostic change on the other border–between autism and other disorders
3% spacial clustering
11% increased parental age

Prof. Bearman suggests that the increased parental age factor is likely genetic in origin. Increased parental age leads to more copy number variations (CNV), leading to more autism.

I don’t expect this to change the “there can’t be a genetic epidemic” slogan. At this point it isn’t proven that this large factor is genetic. But it is possible.

There is still a large fraction of the increase which is unaccounted for. Prof. Bearman warns at the end that a search for a “quick and dirty” answer may not be advancing science.

I take “quick and dirty answer” to mean vaccines.

The problem is highly complex. The next steps in this study will be very difficult. The social influences on increasing autism prevalence can amplify other factors. Finding possible causes for a real increase in autism incidence will be complicated by other factors. But unless someone quantifies and understands those factors, the likelihood is very low of ever finding causes of autism which might drive part of the increase in prevalence.

Social influences on the rise in autism prevalence

19 Apr

How much does “awareness” affect the increase in autism prevalence? Awareness has many aspects. News reports. Getting doctors to look and test for autism. One way is when someone in your neighborhood has an autistic kid. Does that have a measurable effect? The answer is yes.

In their paper, Social Influence and the Autism Epidemic, Ka?Yuet Liu, Marissa King, and Peter S. Bearman of Columbia University look into this using data from the California Department of Social Services (CDDS).

You may recall that I recently blogged on a paper where Marissa King and Prof. Bearman recently took a look at how diagnostic changes have affected the autism counts in the CDDS. The paper is Diagnostic change and the increased prevalence of autism.

Luckily, Steven Novella has already discussed this paper in detail in Social Factors in Autism Diagnosis. Also, the Autism Natural Variation blog has discussed this and extrapolated the current trends in The Administrative Prevalence of Autism is a Bass Distribution.

All this intro aside, what did Liu, King and Bearman find?

Despite a plethora of studies, we do not know why autism incidence has increased rapidly over the past two decades. Using California data, this study shows that children living very close to a child previously diagnosed with autism are more likely to be diagnosed with autism. An underlying social influence mechanism involving information diffusion drives this result, contributing to 16% of the increase in prevalence over 2000–2005. We eliminate competing explanations (i.e., residential sorting, environmental toxicants, and viral transmission) through seven tests and show that information diffusion simultaneously contributed to the increased prevalence, spatial clustering, and decreasing age of diagnosis.

In other words, if you live in California and you live near a family with an autistic child, you are more likely to obtain services from the CDDS for autism for your own child and be included in the CDDS count.

I’ve been meaning to blog this for a while. Prof. Bearman discussed this in a talk he gave at NIH, Understanding the Increased Prevalence of Autism. The link will take you to a page where you can watch the lecture. Sorry, I can’t figure out to embed the talk.

The talk was very interesting. Prof. Bearman discusses the autism cluster they found. He also discusses this social awareness effect.

A few notes from the lecture:

Prof. Bearman can account for much of the increase in the CDDS count. Four contributions he found are:

with diagnostic change–about 27% of the increase
advanced parental age–about 11% of the increase
spatial structure–about 2-3% of the increase
social mechanisms–about 16% of the increase

About 40-50% of the increase is still unaccounted for in his team’s analyses.

For those who are wondering:his team has not ignored vaccines. He doesn’t discuss them much,

One thing Prof. Bearman did find: vaccination rates go down in areas where autism organizations exist. For every autism organization in a given zip code, the exemption rate for personal beliefs increases by 24%.

One could ask whether this is just a sign that higher autism rates are the factors? In other words, is the presence of an autism organization a proxy for autism rate? The answer is no. The vaccine exemption rate does *not* depend on autism prevalence, just the presence of autism organizations.

In other words, autism doesn’t scare people out of vaccinating. Autism organizations do that.

Prof. Bearman’s group has two more papers I await: “Autism and the Hispanic Puzzle” and “Autism and Vaccines, revisited”. At the time of the lecture, the vaccine paper was “under review”.

The CDDS data are far from the “Gold Standard” dataset that some people have claimed. However, it is a valuable dataset and it is good to see a group like Prof. Bearman’s take on a serious, detailed look at it. If there is a real increase in the autism prevalence, it will take teams studies like this to find it.

PBS Frontline: The Vaccine War

16 Apr

I first heard that the show Frontline, from the Public Broadcasting Service (PBS), would be doing a show on “The Vaccine Wars” by reading comments posted online by supporters of groups like Generation Rescue. I was somewhat taken aback that they were happy to hear this was coming as Frontline is a very evidence-based show. I couldn’t see it being very supportive of Jenny McCarthy.

Frontline’s website had this to say about the show:

Public health scientists and clinicians tout vaccines as one of the greatest achievements of modern medicine. But for many ordinary Americans vaccines have become controversial. Young parents are concerned at the sheer number of shots–some 26 inoculations for 14 different diseases by age 6–and follow alternative vaccination schedules advocated by gurus like Dr. Robert Sears. Other parents go further. In communities like Ashland, Oregon, up to one-third of parents are choosing not to vaccinate their kids at all. And some advocacy groups, like Generation Rescue, argue that vaccines are no longer a public health miracle but a scourge; they view vaccines as responsible for alarming rises in certain disorders, including ADHD and autism. This is the vaccine war: On one side sits scientific medicine and the public health establishment; on the other a populist coalition of parents, celebrities (like Jenny McCarthy), politicians and activists. It’s a war that increasingly takes place on the Internet with both sides using the latest social media tools, including Facebook and Twitter, to win the hearts and minds of the public.

I guess I am not on the “latest” social media tools, but I am blogging on the topic so I figure I count as a small part of the “war”.

Reading the above I felt that “The Vaccine Wars” was not going to be the Jenny McCarthy friendly show some were expecting. Being put on the side against “scientific medicine” is usually not a good thing. Also, Generation Rescue tries to pitch itself as being “pro safe vaccine” rather than anti vaccine. I doubt they would like to see themselves as being characterized as arguing “that vaccines are no longer a public health miracle but a scourge”. Then again, times may be changing with the founder of Generation Rescue stating:

With less than a half-dozen full-time activists, annual budgets of six figures or less, and umpteen thousand courageous, undaunted, and selfless volunteer parents, our community, held together with duct tape and bailing wire, is in the early to middle stages of bringing the U.S. vaccine program to its knees.

That’s hard to fit into a “pro safe vaccine” image.

One way to tell for certain if Generation Rescue and other groups are afraid of upcoming media attention is when they start attacking spokespeople like Paul Offit (chief of infectious diseases at the Children’s Hospital of Philadelphia, and co-inventor of the RotaTeq vaccine against rotavirus). When that happened (recent blog posts on the Age of Autism, resurrecting old, incorrect information) I knew it was likely that “The Vaccine Wars” was not going to be a pro-Jenny program.

As it turns out, a video clip has been added to the Frontline website for “The Vaccine Wars”:

And, guess what, Dr. Offit was interviewed by Frontline for the piece.

The show airs on April 27th, and will be available online then as well.

Perhaps it is time for those who support the vaccine-causation idea to re-evaluate their position. I can’t tell how many times I’ve been told I need to be “open minded” about the subject. Open minded includes being willing to admit that your ideas on vaccines-causing-autism were wrong.

Let’s see–

One of the main proponents of the idea, Dr. Andrew Wakefield, was found to be unethical and dishonest
The two main theories, really the only two theories, have failed (“not even close”) in the courts
The media is moving away from giving the vaccine-causation idea much weight.

Of course, maybe I’m wrong. Maybe FrontLine will finally tell the story the vaccine-causation groups believe. Maybe they will uncover the vast conspiracies that are hiding the truth. Maybe. I doubt it.

autism epidemic science, autism vaccine science

27 Jan

Ex Derdrie Imus Environmental Center for Pediatric Oncology team leader Philip J. Landrigan is the latest scientist once associated with the debunked vaccine causation ideas to repudiate those ideas in a scientific journal.

Writing in Current Opinion in Pediatrics, Landrigan has published ‘what causes autism? Exploring the environmental contribution’ in which he explores what might be a plausible environmental causation. He also touches on genetics and the so-called ‘autism epidemic’.

Touching on genetics, he states:

Genetic and familial factors are unquestionably involved in causation of autism [4]. Families with multiple cases have been described. Autism has repeatedly been seen in sibs and twin pairs. Concordance in monozygotic twins is
reported to be as high as 70% [15], and, when the broader phenotype of autism is considered, concordance in monozygotic
twins approaches 90%. Concordance rates for autism in dizygotic twins appear no higher than among singleton siblings. Families with autistic children may contain members with ‘autistic traits’ such as social isolation or tendency toward repetitive behavior [13]. Autism occurs in a number of genetic conditions, among them Fragile X syndrome, Down syndrome, Cohen syndrome, Angelman syndrome [16] and Rett syndrome [17].

Regarding genetics as a whole Landrigan claims that autism can already be accounted for to the tune of between 7 – 8%. In an email to me he stated:

THE FRACTION OF AUTISM CASES THAT CAN RELIABLY BE ATTRIBUTED TO GENETIC CAUSES WILL CERTAINLY INCREASE AS MORE RESEARCH COMES IN

By how much though? No idea and Landrigan wouldn’t be drawn.

Regarding the ‘epidemic’ Landrigan states:

The reported increase in prevalence of autism has triggered vigorous debate as to whether the trend reflects a true increase in incidence, or is merely a consequence of expansion in the definition of ASD and greater awareness, improved diagnosis and better reporting [11]. This highly controversial question is not yet settled [14]. A
recent critical analysis concludes that increases in recognition, changed diagnostic criteria, and changing public
attitudes about autism have played a major role in catalyzing the upward trend in reported prevalence. This analysis observes, however, that the possibility of a true rise in incidence cannot be excluded [12].

Which should be – if one is truly interested in following the science so far – the correct conclusion. In other words, nobody really knows but the recent increases in recognition, changed diagnostic criteria and changing public attitudes (amongst other things) have played a major role.

In relation to vaccines, Landrigan states unequivocally that:

To address the issue, a series of studies was undertaken in the US, the UK, Europe and Japan. None of these studies have found any credible evidence for a link between vaccines and autism [12]…..Fear of autism does not justify failure to vaccinate children against life-threatening diseases [75].

In an email to me Landrigan stated:

IT WAS RESEARCH THAT NEEDED TO BE DONE. BUT NOW THAT WE HAVE MORE THAN DOZEN, HIGH-QUALITY NEGATIVE STUDIES OF THE ISSUE IT IS TIME TO MOVE ON…

I’m not sure it was research that needed to be done given the extremely tenuous hypotheses that began the various vaccine/autism strands but I agree that it is time to move on.

I was somewhat surprised at this paper as I had become used to seeing Landrigan’s name associated with those who believe vaccines cause autism and certainly his involvement with Derdrie Imus would indicate his belief in that set of ideas. It was a nice surprise to see that he was sticking to the science.

So what can we draw from this? First and foremost we have to say that a colleague of Derdrie Imus stating publicly that vaccines don’t cause autism is the biggest red flag so far that even the scientists who once gave credence to those ideas are moving away from them. Secondly we can say that althoough we cannot preclude the idea of a real actual increase, the major role in causing an increase in autism numbers still remains the combination of increased recognition, changed diagnostic criteria, changed public attitude, diagnostic substitution, more available locations for gaining a diagnosis and more doctors trained to give diagnoses. Lastly we can say that here is a toxicologist who acknowledges that there is a strong genetic component and that that component is likely to increase.

Autism Clusters Found: areas with high incidence of autistic children

1 Jan

Researchers at the U.C. Davis MIND Institute has discovered regions in the state of California that have notably higher autism incidence. But the story is more complicated, and more sad, than one might think at first. Instead of indications of an “autism epidemic”, these clusters point to the fact that minority and poor children are much less likely to receive autism diagnoses.

I don’t have the paper yet (I’m still trying to find the abstract), but articles in the Woodland Daily Democrat and the San Diego Union-Tribune are reporting the story.

The clusters do not appear to point to environmental causes. Instead…well, read for yourself:

Researchers said that in this investigation the clusters probably are not correlated with specific environmental pollutants or other “exposures.” Rather, they correlate to areas where residents are more educated.

Children with autism diagnoses in these clusters are more likely to be White and have parents with high education levels. Again, a quote:

“In the U.S., the children of older, white and highly educated parents are more likely to receive a diagnosis of autism or autism spectrum disorder. For this reason, the clusters we found are probably not a result of a common environmental exposure. Instead, the differences in education, age and ethnicity of parents comparing births in the cluster versus those outside the cluster were striking enough to explain the clusters of autism cases,” said senior author Irva Hertz-Picciotto.

Kids in the “clusters” are about twice a likely to be diagnosed autistic and kids in nearby areas.

Twice as high.

To the many of us armchair epidemiologists who who have looked closely at the California Department of Developmental Services (CDDS) data, this comes as no surprise.

For me, the most memorable discussion of the autism clusters came from Autism Diva, in her post from July 1997, Malibu and Compton: Compare and Contrast.

Here is a graph from that post:

The South Central Regional Center, in a predominantly non-White, poor area of the Los Angeles basin, had an administrative prevalence of 33 per 10,000. Compare that to Westside Regional Center with a prevelance of 84. Westside is a much more affluent are with a higher proportion of White families.

From the San Diego Union-Tribune:

“There is mounting evidence that at least some of this clustering results from the greater access and utilization of services by those with more years of schooling,” the UC Davis researchers wrote.

Yes, there is a certain “I told you so” moment here. This blog, Autism Diva, Autism Natural Variation, Autism Street and others have been pointing out the apparent autism clusters in the raw CDDS data for years. Long before I started blogging. But the real story isn’t the effect such clusters have on the idea of the “autism epidemic”. Rather, this is a clear indication that we are underserving the disabled in our minority and poor communities. This is just plain wrong.

It is long past time for real autism advocacy organizations to work on increasing awareness and access to services in underserved areas. The autism “clusters” are probably not real. From where I sit, what is real are the “anti–clusters” of undiagnosed autistics, minorities, the poor, and, yes, adults.

CDC report 1 in 110 kids are identified autistic

19 Dec

You’ve probably already heard–the CDC’s estimate of the autism rate was announced as 1% today. This was published in an MMWR came out today, with the new CDC prevalence estimate of 1 in 110. I made some notes on the conference call, but I thought it worthwhile to make a few comments on the document itself.

This is the third in the autism prevalence MMWR’s. The first was
Prevalence of Autism Spectrum Disorders — Autism and Developmental Disabilities Monitoring Network, Six Sites, United States, 2000

and

Prevalence of Autism Spectrum Disorders — Autism and Developmental Disabilities Monitoring Network, 14 Sites, United States, 2002

This new one is titled

Prevalence of Autism Spectrum Disorders — Autism and Developmental Disabilities Monitoring Network, United States, 2006

In each they estimate the prevalence for 8 year olds. So, the 2000 study was on children born in 1992 and the 2002 study was on children born in 1994. They found prevalences of 1 in 166 (200) and 1 in 150 (2002), respectively.

The new prevalence is 1 in 110 for 2006 (8 year old children born in 1998). This is a big jump, no doubt. It is worth taking very seriously. Unfortunately, it isn’t as simple as saying, “the number of autistic children has increased”.

As the authors note in the introduction:

Since the early 1990s, the number of persons receiving services for ASDs has increased substantially. However, identifying children for services for autism might not be equivalent to using consistent diagnostic standards to identify persons in the population because services within communities are not available uniformly to all persons with ASDs. For this reason, studies that rely exclusively on single-source administrative datasets (e.g., disability service records or annual reports of special education counts) most likely underestimate ASD prevalence and might not adequately capture changes in the ASD population over time

Most of the states reporting in the ADDM use more than a single source. Most use medical and educational records. Those that use a single source (e.g. Florida) show lower prevalence estimates.

Let’s get back to that 1% estimate. This is a big jump in the prevalence–with the previous prevalence being 1 in 150 (about 0.67%). Yes, it should be taken seriously, but at the same time 1% is not a surprising number. The authors list 5 studies that show a prevalence >1%, using other methods.

Note that this is for the 1998 birth cohort, children born 4 years after those studied in the previous MMWR. I bring this up because the “buzz” before the MMWR was discussing this as the 1996 cohort. The studies are not spaced out evenly in time–2000, 2002, 2006.

Methodology
The methodology is through a record screen, not through direct observation of children:

Children aged 8 years with a notation of an ASD or descriptions consistent with an ASD were identified through screening and abstraction of existing health and education records containing professional assessments of the child’s developmental progress at health-care or education facilities.

If on review of the records, the child is deemed to meet the DSM-IV criteria for autism, he/she is counted. This is a good way to get an estimate, but there is a lot of room for children to fall through the cracks, in my opinion. As such, it is and has always been, an underestimate. In some cases, it is probably a very large underestimate. As will be shown below, there is a big variation by state–a factor of 3. I don’t think anyone really believes that the autism prevalence in Florida, or the prevalence amongst Hispanics is much lower than in other states or other ethnicities.

It is interesting to note that the ADDM network does find a significant number of children whom they (the ADDM) categorize as autistic even though they haven’t been given that diagnosis before. About 23% of the autisistics counted in the 1% value were not identified before the ADDM did their review.

That’s worth repeating–about 23% of 8 year olds identified as autistic were mislabeled as non-autistic by their schools, parents and doctors. That’s an interesting fact for those who claim that autism is easily identified.

The CDC study is not capable of explaining whether part of the increase represents a “real” increase in the number of autistic kids. It certainly can’t go into whether or not any specific proposed cause is valid. However, one can use the data to test hypotheses. This type of study just isn’t capable of making claims about causation.

States Reporting to the ADDM

This new study covers children born in 1994 living in 11 states:
Alabama, Arizona, Colorado, Florida, Georgia, Maryland, Missouri, North Carolina, Pennsylvania, South Carolina, and Wisconsin.

Note that this is different from the last MMWR, which looked at kids born 2 years earlier (1996) and included sites in:
Alabama, Arizona, Arkansas, Colorado, Georgia, Maryland, Missouri, New Jersey, North Carolina, Pennsylvania, South Carolina, Utah, West Virginia , and Wisconsin.

The new study added Florida, but took out Arkansas, New Jersey, Utah and West Virginia. These changes do make it more difficult to compare the prevalence data. They do not explain the increase. By that I mean, it isn’t as though the low prevalence states were removed from the previous MMWR study and high prevalence states were added.

I would have been very interested what happened to the prevalence in New Jersey. The last two MMWRs had New Jersey at about 1%. A good comparison would be if that state had the same autism prevalence or a higher value.

Prevalence by state

Data in Table 2 from the MMWR. Data from 11 states were reported. The prevalence ranged from 4.2 (Florida) to 12.1 per 1,000 (Missouri and Arizona). That’s a big spread, a factor of 3. The highest prevalence was for males in Missouri–19.1 per 1,000 (1.9%, or 1 in 52).

There was some variation in the male:female ratio, from 3.2 (Alabama) to 7.6 (Florida). Again, this shows that there is a big variation by state in how autistics are identified.

Variation by ethnicity.

There is a large difference in the prevalence by ethnicity. This also varies by state. For example, there is a 9.4 White-to-Hispanic ratio in Alabama, but the same ratio is only 0.7 in Florida. In general, Whites are identified more often than either Hispanic or African Americans.

We have a lot of work to do in making sure minorities are correctly identified and getting appropriate services and supports.

Earlier age of identification.

The median age of autism diagnosis is about 4.5 years. This is a big jump down from the 2002 data, which had a median of 5 years. That is a good thing.

This is worth a couple of comments. First, there is still room for improvement. Most of the children had development concerns noted in their records before age 2. The obvious question is whether these children could have been identified sooner. This was one comment stressed by the CDC in the conference call.

It is also worth noting that autism isn’t “obvious” or “easy” to identify autistics. 4.5 years old is the median age.

It is also worth noting that the big jump down in median age of identification is a very clear indicator that, yes, people are getting better at identifying and diagnosing autistics.

The range of age of identification is as low as 2 months (!) to as high as 106 months. The low end is pretty remarkable. I don’t think there are any tests qualified for such young children. At the high end, that is nearly 9 years old. Again, this goes to the idea that autism is not obvious.

One complaint that is always used in these discussions is “what, are you saying that no one noticed these kids?”. No. They likely had other diagnoses or that some concerns were noted about development for them.

Number of kids receiving special education services.

Table 3 of the report is quite interesting. They show for six states what fraction of identified autistic kids are getting special education, and under what primary label.

In Colorado, 76% of autistic students are in special education, while in Arizona it is 96%. Is there really such a big difference in the needs of these kids from state to state?

Colorado has only 34% of the autistic students under the primary category of autism. Compare that to Maryland with 76%. Again, it is pretty clear that there is a lot of variation in how special education services are granted by state.

Cognitive Functioning

From the MMWR:

Data on cognitive functioning are reported for sites having IQ test scores available on at least 70% of children who met the ASD case definition. The proportion of children with ASDs who had test scores indicating cognitive impairment (IQ ?70) ranged from 29.3% in Colorado to 51.2% in South Carolina (average: 41%)

I find this information rather interesting. Most of the children with IQ data were not cognitively impaired.

2004 Prevalence data.

There was also a small appendix released today, with information on 2004 prevalence data (note that the study noted above is for 2006). Those data show a prevalence of 8 in 1,000, or 1 in 125. This is a “smaller scale effort”

It is interesting to put the data from the various studies into a timeline:

2000 originally 1 in 166, revised to 1 in 150 (6.7 per 1,000) (1992 cohort)
2002 1 in 152 (6.6 per 1,000) (1994 cohort)
2004 1 in 125 (8.0 per 1,000) (1996 cohort)
2006 1 in 110 (9.0 per 1,000) (1998 cohort)

If you recall, David Kirby claimed the new CDC data would support his hypothesis that the Hepatitis B vaccine caused an upsurge. Mr. Kirby mistakenly assumed that the 1% figure would be for the 1996 birth cohort. Mr Kirby then correlated the jump from 1 in 150 to 1 in 100 with the uptake of HepB vaccination in that birth cohort. He stated (incorrectly, we now know):

But according to the CDC’s National Immunization Survey (which also includes parental telephone interviews), only 8% of infant children received the Hep B vaccine in 1992, when that birth cohort showed an ASD rate of 67-per-10,000.

By 1994, the number of children receiving Hep B vaccine had reached just 27% — and the cohort showed a similar ASD rate.

But the Hep B coverage rate had risen to 82% by 1996, when that cohort’s ASD rate rose to around 100-per-10,000.

So, there was a smaller jump that correlates with the uptake in HepB in the 1994 cohort–the rate increased from 0.66% (1994) to 0.80% (1996). Then, two years later, there is a similar jump, from 0.80% (1996) to 0.90%. But, this time without the big increase in HepB vaccination.

Not so dramatic a story with the real data. Just a constant rise.

Final words

I hope this highlights some of the information in the study. I wish I had the time to spend to make this summary a bit easier of a read. But, there are other posts to write. Like one talking about Autism Speaks and the way they are capitalizing on the new prevalence numbers with a very deceptive graph.

David Kirby: No friend to my autistic kid

27 Oct

David Kirby is certainly no friend to my autistic child.

I don’t know why I let David Kirby annoy me. It is a pretty safe bet that whenever he blogs he will write something that rubs me the wrong way. Whether it is his clear lack of science acumen or his faux fence sitting “I’m just trying to spark a national debate” ruse, he never fails to write something offensive.

Recently he responded to the very strong possibility that the number of autistic adults is much higher than previously thought with what amounts to essentially, “Autistic adults? Nope, I’ve never seen ’em. They must not exist”.

The right answer in my view would be, “We need to confirm this right now and find out who may be getting no support or the wrong support.” That’s what a friend to my kid would say. By denying the existence of autistic adults Mr. Kirby has shown himself to be about as far from a friend as I could imagine.

In his recent interview with Sharyl Attkisson Mr. Kirby noted that he didn’t see any autistics on the subway or in his neighborhood, therefore there can’t be 1 in 100 autistic adults. Therefore, according to his logic, there is an autism epidemic. Of course he says this is to support the idea that we need to take the vaccine issue seriously.

It was nonsense when he first said it and I pointed it out. I thought that having embarrassed himself on national TV, Mr. Kirby would quietly drop the idea that somehow “I know ’em when I see ’em” is either valid or respectful. I’ve watched Mr. Kirby for too long to even hope that he would apologize or do a real retraction without real pressure but I will say I was surprised to see him write a blog post basically defending his autistic-radar.

In a recent blog post Mr. Kirby has expanded his scope of not-finding autistics. It isn’t just his recent subway ride that was devoid of adult autistics, it is his entire life:

I have lived in many different cities, worked at nine different jobs, and met thousands of men and women throughout my years. I cannot recall people who showed the characteristics of high-functioning autism, though I must have met some along the way, at least in passing. But there were not 1-in-60 boys with ASD in my schools and there are not 1-in-60 men with ASD in my area. I think I would have noticed them by now.

Repeated for emphasis:

I cannot recall people who showed the characteristics of high-functioning autism

In an entire lifetime, no one who might be high-functioning autistic?

David Kirby has been around the autism community for a while now. Somehow I think he must have seen some adult with high functioning autism. Are we to believe that no autistic adults attend the DAN conferences, the Autism One conferences, or the myriad other alternative medicine conferences that hold David Kirby as a hero? Are we to believe that no autistic adult parents of autistic children attend these conferences?

One specific question that popped into my mind: Has Mr. Kirby never been to a conference with Teresa Binstock? Ms. Binstock is one of the authors of Autism: a novel form of mercury poisoning (a faux-journal paper in Medical Hypotheses). Ms. Binstock is also reported to be an autistic adult (Asperger syndrome). Mr. Kirby has never met her? Possible, but unlikely.

According to his interview Mr. Kirby’s criteria for Asperger syndrome are:

“restrictive, repetitive and stereotypical patterns”

“interests and behaviors that are abnormal”

“Repetive motor mannerisms such as hand or finger flapping”

“Significant impairment in social, occupational and other important fuctions”

I guess as Mr. Kirby was passing people on the subway platform he had some test of social functions? He can tell what your interests are (and somehow label them abnormal) just by looking at you?

For Mr. Kirby’s edification, here are the DSM-IV criteria:

(I) Qualitative impairment in social interaction, as manifested by at least two of the following:
(A) marked impairments in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction
(B) failure to develop peer relationships appropriate to developmental level
(C) a lack of spontaneous seeking to share enjoyment, interest or achievements with other people, (e.g.. by a lack of showing, bringing, or pointing out objects of interest to other people)
(D) lack of social or emotional reciprocity

(II) Restricted repetitive & stereotyped patterns of behavior, interests and activities, as manifested by at least one of the following:

(A) encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
(B) apparently inflexible adherence to specific, nonfunctional routines or rituals
(C) stereotyped and repetitive motor mannerisms (e.g. hand or finger flapping or twisting, or complex whole-body movements)
(D) persistent preoccupation with parts of objects

(III) The disturbance causes clinically significant impairments in social, occupational, or other important areas of functioning.

(IV) There is no clinically significant general delay in language (E.G. single words used by age 2 years, communicative phrases used by age 3 years)

(V) There is no clinically significant delay in cognitive development or in the development of age-appropriate self help skills, adaptive behavior (other than in social interaction) and curiosity about the environment in childhood.

(VI) Criteria are not met for another specific Pervasive Developmental Disorder or Schizophrenia.”

Here’s another hint: if diagnosing ASD’s was as simple as a checklist there wouldn’t be tests like the ADOS.

Mr. Kirby continues the old ruse that autistics are so obvious that one couldn’t possibly miss them, even in passing. Contrary to Mr. Kirby’s assertion, it is possible that he could have missed some autsitics in his subway travels. When the autism rate for children in Cambridgeshire was recently reported, the researchers noted that a large fraction (1/5 to 1/3) of autistic students were undiagnosed. Yes, even educational professionals who spend every day with a kid can miss the fact that the child has an ASD.

In his blog post Mr. Kirby bolsters his argument with a quote from Anne Dachel, probably best known to readers here as an blogger at the Age of Autism. Ms. Dachel states:

“an insult to thousands of teachers and counselors and doctors – who apparently ‘stupidly’ ignored these kids in the past. If they were always here, but we just called them something else, then what did we do with them?”

I am always saddened when an educator like Ms. Dachel confuses intelligence with knowledge. Intelligence (smart/stupid) is not the same thing as knowledge (or ignorance). When previous generations didn’t diagnose a child with an ASD there were many reasons. One big reason–the diagnostic criteria were different then. That is and example of ignorance. I feel silly pointing this out to an educator, but in 1980 they didn’t know (in fact couldn’t know) that the diagnostic criteria would be different in 2000. How many times have we heard, “autism wasn’t covered in medical school back then”? This is used to “show” that autism was rare then. Well, if they didn’t get the training, they were very likely ignorant of the differences between autism and other disabilities. They were certainly unlikely to know the diagnositic criteria for Asperger syndrome, since it didn’t exist at the time.

To answer Ms. Dachel’s question, “what did we do with them”: many autistics services were served under the label of mental retardation. This isn’t even speculation. In a recent study King and Bearman showed that a large number of autistics in California were diagnosed as having mental retardation before 1987. As the criteria changed and awareness grew, these individuals (both children and adults) were also given autism diagnoses. They checked the actual records of actual people and documented it.

To further answer Ms. Dachel’s question, “what did we do with them”: many of “them” were unserved–just like today. Remember that study in Cambridgeshire we just mentioned?

Back to David Kirby’s blog post: he shows us that he is truly “concerned”:

In my opinion, to shrug and treat this story as if things have probably always been this way is, frankly, wishful thinking and unsettling.

It is Mr. Kirby’s response that is unsettling. Heck, it is beyond unsettling. Way beyond.

I think his response the NHS report (that there are 1 in 100 autistic adults) by claiming that since he can’t see “them”, “they” don’t exist is beyond wishful thinking and unsettling. Mr. Kirby acts as though the study doesn’t exist. Worse, he acts as though it shouldn’t exist.

I usually try to avoid speculating on motivations. But, I can’t help myself with these latest comments by Mr. Kirby. Why did he feel the need to downplay the existence of adult autistics in high numbers? The report that there is a high number of unidentified autistic adults is a direct threat the the idea that vaccines caused an epidemic of autism. How does that play to someone who has made a career out of “Evidence of Harm. Mercury in Vaccines and the Autism Epidemic: A Medical Controversy”.

Consider, if you will, what happened when people like Mr. Kirby pushed the idea of an epidemic of vaccine-induced autism. When the ideas came forward that the MMR vaccine or the vaccine preservative thimerosal could be causing autism, the scientific community took it seriously and responded with multiple studies looking for better evidence. But now that there is evidence of a large contingent of adult autistics, Mr. Kirby joins the denialists and defends the old-guard thinking. Ironic, that.

It has always been a reasonable assumption that there is a large contingent of unidentified autistic adults. The active denial of this possibility has long bothered me. The denial in response to the UK survey of autistic adults is just beyond the pale.

Mr. Kirby is just no friend to my kid. My kid needs advocates who will fight to make a better world for autistics. How can we do that if we deny their existence? How can we prepare for the kids of today to become adults if we don’t start supporting autistic adults now?

Sharyl Attkisson interviews David Kirby…and oh is it bad

8 Oct

Have a look for yourself:

http://cnettv.cnet.com/av/video/cbsnews/atlantis2/player-dest.swf
Watch CBS News Videos Online

David Kirby, interviewed by Sharyl Attkisson. Talk about faux-news. For those luckily unfamiliar with Ms. Attkisson, here are some of the pieces done on this blog about her. Ms. Attkisson has a history of interviewing other members of the press and not being critical at all of their unsupported claims. She did this with Bernadine Healy, who made some unfounded claims about the IOM. When a study came out disproving a study by Maddy Hornig on mice and thimerosal that is, Ms. Attkisson blogged the Thoughtful House (Andrew Wakefield) press release on the subject. There’s more, but that gives you a taste of her history.

Today she interviewed David Kirby, author of “Evidence of Harm” and Huffington Post blogger.

To start, David Kirby apparantly has rewritten his book (yes, that is sarcasm). It is titled, “Evidence of Harm, Mercury in Vaccines and the Autism Epidemic: A Medical Controversy”.

But according to the interview, his book isn’t primarily about mercury in vaccines. Instead it is all about “increasing environmental exposures, toxins in children throughout the 1990’s and into the early 2000’s from both mercury background mercury environmental mercury which is on the increase and also mercury and other heavy metals and toxic metals that are included in vaccines that we give our children.”

Notice how thimersosal (mercury in vaccines) is downplayed compared to environmental mercury. That’s called revisionist history. Take a look at the back cover from the book (click to enlarge):

Back Cover from David Kirby's Evidence of Harm

Back Cover from David Kirby's Evidence of Harm

A commenter on this blog called the recent National Children’s Health Survey to be the worst sort of prevalence study. It can get much worse. For example–according to David Kirby, when he went through the subway he didn’t see anyone obviously autistic. Yes, David Kirby, epidemiologist and diagnostician has found a dramatically low prevalence amongst the New York subway riders.

David Kirby reminds us all that Asperger’s syndrome is a disability. Mr. Kirby, go back and tell that to Lenny Schafer, the “commenter of the week” on your blog, the Age of Autism.

If someone made a comment on this blog like Mr. Shafer did he would be booed off the stage. Here’s an excerpt:

And let us hope that the upcoming DSM-V gets clearer about defining autism only as a disability — and kicks the high functioning ND autism squatters onto the personality disorder spectrum where they belong.

Your blog gave him a free T-shirt. Don’t lecture us about disability.

Dr. Thomas Insel, director of the National Institutes of Mental Health and chair of the Interagency Autism Coordinating Committee declined to be interviewed by Ms. Attkisson.

A sincere “good job” goes out to Dr. Insel. After the way Ms. Attkisson showed a clear bias in doing her story on Dr. Offit, I can completely understand Dr. Insel declining the interview.

The second half of the interview discusses Mr. Kirby’s new book, the use of antibiotics on large farms.

No, seriously, they moved from Autism to animal farms.

Way to plug David Kirby’s new book, Sharyl!

1 in 100 adults are autistic

30 Sep

A recent report by the Information Centre of the UK’s National Health Service says that the autism prevalence for adults is about 1 in 100.

The report, Autism Spectrum Disorders in adults living in households throughout England, states:

Using this recommended threshold score on the ADOS, 1.0%of the adult population had ASD. The rate was higher in men (1.8%) than women (0.2%), which fits with the profile found in childhood population studies.

This isn’t very new news, Anthony Cox and Kev Leitch on this blog have already discussed this.

I would suggest that the first reaction from pretty much everyone (including myself) was wrong.

What should the take-away message be from this?

Simple–there are a lot of unidentified adult autistics who are likely getting little, no, or inappropriate support.

From the report:

“Perhaps most important of all is the finding that adults with ASD are socially disadvantaged, less well educationally qualified, less able intellectually and possibly under-supported by services. Much of this could be alleviated with greater involvement of existing established social, educational, welfare and health care services.

Another point that really sticks out to me is:

There was no indication of any increased use of treatment or services for mental or emotional problems among people with ASD.

We don’t know if this is because they don’t need more services or they just aren’t getting them.

Two more statistics are also worth pointing out: 4.5% of unmarried male adults are identified as ASD. 8% of male adults in social housing are identified as ASD.

That’s huge. Imagine walking through a specific housing complex and 1 in 12 men you see are autistic.

Now that I am done lecturing everyone (including myself) about what I think the important message is from this report, let’s take a look at the report itself. Specifically, let’s consider the complaints that are being levied against it.

The first thing that struck me is that this is a report, not a published study. It is not, to my knowledge, peer reviewed in the same sense as a journal article. It is in the same class as the MMWR reports that the CDC puts out (a government report) that are used by almost everyone to discuss the prevalence of autism. So, if you use 1 in 150 or 1 in 166 prevalence numbers, don’t complain about this UK report being non-peer reviewed.

People are complaining about how the study was conducted. Here is the basic process:

A. Phase one AQ-20 self-completion screen
B. Selection of cases for phase two assessment
C. Phase two ADOS assessment of a subset of cases
D. Weighting to adjust for selection probabilities and non-response.

This was not worded well, since many people assume that the phase one screen only used the AQ-20. As I will discuss below, this is not the case.

The initial screen started by identifying addresses that were residences, and selecting some by random selection. They selected 13,171 possible households for phase-1. Of these, 57% agreed to respond.

9% of sampled addresses were ineligible because they contained no private households, while 4%were addresses of unknown eligibility (see Section 3.2.5). This left an estimated base of 13,171 known eligible or probable eligible households for the phase one interview. The proportion of selected adults who agreed to take part in an initial interview is shown in Figure 3B. At the phase one interview, 57% of those eligible agreed to take part in an interview. This included 50 partial interviews where the respondent completed the service use and CIS-R modules, but did not reach the end of the interview.

These interviews were not just the AQ-20 screen, as noted below:

The phase one interviews were carried out by NatCen interviewers. These included structured assessments and screening instruments for mental disorders, as well as questions about other topics, such as general health, service use, risk factors and demographics. These interviews lasted about 90 minutes on average.

90 minutes per interview, with 7,353 full interviews works out to 5.3 man-years of labor.

This was no small effort.

Many complaints I have seen concentrate on the AQ-20 test. The full AQ test, or Autism Quotient, is a product of the Cambridge Autism Research Centre, and has been studied already. It is usually a 50 question test, but it was shortened to 20 questions (hence AQ20) and adapted for the NHS survey. They shortened the AQ to save time.

Many people have been confused that this short questionnaire was the method used to make the autism diagnoses. People pull questions out and question whether they could be used to diagnose autism. The AQ20 wasn’t used to make the diagnoses. It was only a part of the phase-one, pre-screen, part of the study. The diagnoses were made using the ADOS.

They used the information from phase 1 to select a smaller subgroup for the more intensive phase-2 part of the study. Amongst this smaller group, the researchers chose people they thought were more likely to have psychosis, Asperger syndrome or personality disorder.

7461 respondents provided a productive phase one interview. Of these 58 were proxy respondents and therefore not eligible for the phase two interview (see Figure 3E). A probability of selection was calculated for each respondent based on their answers to the phase one screening questions on psychosis, Asperger syndrome, and personality disorder: as outlined in Section 3.2.6. 5,329 respondents had a probability of selection of greater than zero: 4050 of these also agreed to be recontacted for a phase two interview (76%). After the application of the highest of the four disorder specific sampling fractions, 849 respondents were selected for a phase two interview. Phase two interviews were conducted with 630 of these (74%).

618 of the 630 people who underwent the phase-2 interviews were given the ADOS test. A score of 10 on the ADOS was chosen to indicate a diagnosis of an ASD. Of these, 19 scored above 10 on the test and were diagnosed as having an ASD.

If one took these data to calculate a crude prevalence, a value of 19/618 or about 3% (1 in 32) would be obtained. No one is saying this is an accurate estimate, but it is worth noting for this reason: quite obviously, the phase-1 screen was successful in finding a larger number of autistics than

These data were weighted to estimate a prevalence for the overall study group, including non-responders. They came up with a prevalence of 1% (1.8% for males 0.2% for females).

Here are some of the complaints I have read about this report:

1) They define adult with ages as young as 16.

this is supposed to be a sign that they are trying to fudge the data by including people who are really part of the so-called “epidemic”.

Well, the UK Census defines adults as people age 16 and over. If including 16 and 17 year olds were a problem, one would expect the younger age category to have a much higher prevalence. It doesn’t.

age group 16-44: prevalence 1.1%
age group 45-74: prevalence 0.9%
age group 75+: prevalence 0.8%

(from table 2B)

Another complaint is that there were no ethnic or racial minorities in the group of 19 identified autistics. This is a good check for internal consistency, but it isn’t a valuable check in this case.

The UK has about 90% white population. They tested 618 individuals with the ADOS. If the selection were random in ethnicity, they would have 61 minority participants. A 1% autism rate would lead us to expect 0.6 ethnic minority autistics.

People have complained that the study only shows adults in residential housing. I.e. they didn’t check institutions.

The report is very clear about this (it is even in the title). They note:

The sample for APMS 2007 was designed to be representative of the population living in private households (that is, people not living in communal establishments) in England. People living in institutions are more likely than those living in private households to have ASD, however this group was not covered in the survey reported on here and this should be borne in mind when considering the survey’s account. At the time of the 2001 Census, 2% of the English population aged 16 years or over were resident in a communal establishment.

So, yes, by leaving out those in institutions they didn’t measure the prevalence in the total UK population. That is a limitation of this report. The prevalence in the institutions is very likely to be higher than in residential settings. I.e. they would have found more autistics had they look in institutions and they would have found a higher prevalence overall.

One complaint is that they only identified 19 adult autistics in phase two. This is definitely worth considering as that puts some big error bars on the results. This becomes especially when they try to break the results down by age, gender, or other category.

It has been proposed that one can’t extrapolate from the 19.

But, just for fun, let’s make the assumption that the 19 adult autistics ID’d in phase 2 group (of about 618) are all there would be in the entire group studied (7353).

That would give a prevalence of 25 per 10,000.

This is much higher than people have been claiming the prevalence should be amongst adults. Many people claim the prevalence rate for adults should be about 1 in 10,0000 or 3.3 in 10,000.

To put it simply, those claiming there is an epidemic of autism are off by at least a factor of 7.

Or, to put it another way,

It isn’t a question of whether there are factors such as widening of the criteria or diagnositic substitution/accretion that have caused some of the rise in the autism “rates”. The question is what factors have been in play and how big of an effect did they have.

Another criticism I have seen is that the male:female ratio is quite high, 18:1, as opposed to the 3:1 or 4:1 found in most studies. They found 19 autistics. A 3:1 male:female ratio would lead us to expect 5 females. I’ll let the statisticians tell me if this is significant, but they did find fewer women than I would expect. The report notes repeatedly that the small number of women limits the analysis.

I have been told in the comments on this blog that the study was done cheaply. I wouldn’t be surprised. However, it does represent a significant effort. I am impressed that anyone undertook to do a prevalence study on adults.

This isn’t a definitive or end-all study. Far from it. But it is a reasonable study and a very good start. I hope this is the beginning of a much greater effort to gather more information on adult autistics. It is pretty frightening to think that a very large segment of the autistic population could be undiagnosed and possibly receiving inappropriate supports.

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