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Bravo Age of Autism

20 May

Yep, you read that correctly.

In a recent blog post on the Age of Autism blog, Dr Lorene E.A. Amet wrote about “Testosterone and Autism”. While much of the piece seems to be fighting a straw man (the theme is that Simon Baron-Cohen wants to use testosterone to screen for autism prenatally–without a link to the story or a quote from SBC, I found this difficult to wade through). But, as part of her piece, Dr. Amet wrote:

It is of great concern that studies on testosterone and autism are being misinterpreted, leading to the use of therapies aimed at disturbing steroid hormone production in individuals with autism. Currently, many autistic children may be being treated, without proof of safety and scientific and medical evidence of benefit, with a view to reducing their hormonal secretion of testosterone (Lupron Therapy, Spironolactone). The rationale behind advocating these therapies appears to be based on a misunderstanding of autistic behaviours and without systematic laboratory evidence of abnormal testosterone levels.

I had to double check that I was reading the right blog! I mean, Age of Autism allowed someone to state that the the rationale behind using Lupron to treat autism is “based on a misunderstanding”.

For those who are lucky enough to not know, Lupron as a treatment for autism is the pet project of Mark and David Geier. These are near heroes to the world of Age of Autism, due in large part to their promotion of REALLY bad epidemiology (for example, here, here and here on Epiwonk’s blog) to support the thimerosal/autism link.

The Geiers took the testosterone theory of Dr. Baron-Cohen and ran with it. Ran without knowing what they were doing or where they were going. Somehow they came to the conclusion that Testosterone binds with mercury in the brain, making it difficult to remove the mercury with chelation. Reduce the testosterone in the system, they guessed, and one could get the mercury out. Since in their world autism is caused by mercury, this will “recover” or “cure” people of autism.

Doesn’t make any sense to you? That’s because it doesn’t make any sense. At all.

Even though the idea of using lupron is misguided and potentially dangerous, that doesn’t mean that the groups that sponsor the Age of Autism blog would be willing to out the Geiers, even without specifically naming them, for the unscientific team that they are.

To be honest, I think the Age of Autism editors just missed that paragraph by Dr. Amet before approving it to be published (if they approve at all).

But, it’s there now for all to read. Bravo Age of Autism. Bravo for joining the world of people who find the Lupron Protocol to be based on a “misunderstanding” of the science.

Autism epidemic in Sri Lanka?

8 May

Well, that’s what you might read if/when some other blogs see this new study:Screening of 18-24-Month-Old Children for Autism in a Semi-Urban Community in Sri Lanka. Soon to come out in the Journal of Tropical Pediatrics.

Take a look at the abstract:

All children aged 18-24 months in a defined geographical area were initially screened for autism, using ‘Red Flag’ criteria. All the children with one or more positive ‘Red Flag’ signs were further screened using Modified Checklist for Autism in Toddlers (M-CHAT) translated to Sinhala, followed by a comprehensive clinical assessment. Of a sample of 374 children, ‘Red Flag’ signs were positive in 28 (7.4%). Four children received a diagnosis of autism on clinical assessment giving a prevalence of 1.07% or 1 per 93 in the 18-24-month age group. Sensitivity of M-CHAT was only 25%, and specificity 70%. The high prevalence detected strongly justifies early community-based screening, but a culturally sensitive screening tool needs to be developed for Sri Lanka.

Let me start by congratulating the researchers. We need a lot more information about autism around the world. So far, most of the data is from the US, Canada and Western Europe. We need to know more about autism in other countries, and, more importantly, they need to know more about what is happening in their own countries.

The idea that a “culturally sensitive screening tool needs to be developed” is one that I would like to see explored. The IACC Strategic Plan had initiatives which were directed at screening diverse populations.

I find it interesting that they worked with children so young (18-24 months old). It will be interesting to see how stable those diagnoses are over time as well as if they missed anyone.

The autism prevalence is about 1.07%. One reason I decided to blog this is because it fits with a prediction made by Joseph over 2 years ago in his blog post Moving Toward a New Consensus Prevalence of 1% or Higher.

We do, indeed, appear to be moving towards a consensus of about 1% (or somewhat higher) for autism prevalence. It’s quite interesting to see, and kudos to Joseph for pointing this out 2 years ago.

Generation Rescue: a dishonest autism charity?

6 May

Generation Rescue has a long history of promoting bad science. They even have tried their hand at it themselves before, with a phone survey that was so bad it would have earned a college freshman in epidemiology a failing grade.

So when they came out with their own “study” of vaccination rates around the world, you can imagine I didn’t expect it to be good. In fact, I just avoided it altogether until they sent me an email telling me how good it was.

So I looked.

It was worse than I expected. Far worse.

The “study” is here. Generation Rescue (GR) looks at the vaccine schedules for multiple countries and compares this with the infant mortality rate and autism rates in those countries.

I read it and, Oh…my…god… I expected bad science and poorly/biased interpretations. Instead, what I found was pretty clear evidence that Generation Rescue is knowingly distributing misleading information.

Before you get worried that this post is way long and question whether you really want to read the details, here’s the short version:

1) They compare infant mortality rates between the US and other countries–even though it is clear (according to their own expert no less!) that the US uses different criteria for infant mortality and it isn’t accurate to compare the US infant mortality to that in other countries.

2) They compare autism rates amongst countries to show the US has the highest rate, suggesting that the higher the number of vaccines the higher the autism rate. They just “forget” to tell you that the prevalences for the other countries are from old studies. We can debate why the reported autism prevalence is going up with time, but no one debates that the older studies report lower prevalences than we see now. So, why does Generation Rescue compare prevalence in the US using 2002 data for kids born in 1994 with, say, a Finnish study using 1997 data on kids born as early as 1979? I consider them very biased, but not incompetent enough to miss those fatal mistakes in their study.

3) They claim that the US has the highest vaccination rates and the highest autism rates. They conveniently ignore prevalence from Canada and the UK, which have comparable prevalences to the US and much much lower numbers of vaccines. Yes, you read that right, they left out the well known studies that would show that their conclusions are nonsense.

The worst part is that it is almost certain that Generation Rescue didn’t make an honest mistake. These are so obvious that whoever wrote that “study” had to know he/she was producing what amounts to the lowest form of junk pseudoscience.

For those who want the gory details, here they are:

Infant Mortality Rates

Generation Rescue points out that the reported infant mortality rate is highest in the United States, which also has the most childhood vaccines. All well and good, but can we really compare the infant mortality rates from country to country?

When I type infant mortality rate into a google search, the first hit is a Wikipedia page which, as it turns out, addresses exactly this question.The answer is a resounding “NO”, we can’t compare the US infant mortality rate with that of other countries.

While the United States reports every case of infant mortality, it has been suggested that some other developed countries do not. A 2006 article in U.S. News & World Report claims that “First, it’s shaky ground to compare U.S. infant mortality with reports from other countries. The United States counts all births as live if they show any sign of life, regardless of prematurity or size. This includes what many other countries report as stillbirths. In Austria and Germany, fetal weight must be at least 500 grams (1 pound) to count as a live birth; in other parts of Europe, such as Switzerland, the fetus must be at least 30 centimeters (12 inches) long. In Belgium and France, births at less than 26 weeks of pregnancy are registered as lifeless.

So, who wrote that 2006 article in US News & World Report?

Bernadine Healy.

Yep, the same Bernadine Healy that is Generation Rescue’s favorite “mainstream” doctor.

One has to believe that GR saw that article in Wikipedia and the US News article. They are, after all, Google Ph.D.’s. Given the author was Bernadine Healy, they have to have considered it accurate, don’t you think? And, yet, GR conveniently forgets to mention the differences in how the US and other countries count infant mortality in their vaccines cause autism “study”.

Autism Rates 1: Autism Prevalence by country

Start with the conclusion of the Generation Rescue “study”:

This study appears to lend credibility to the theory that the U.S. vaccine schedule is linked to the U.S. epidemic of autism, particularly when compared to the published autism rates of other countries.

Given this bold claim, it is critical that they use good data for the autism rates. By “good” I mean that they need data that they can accurately compare to the CDC reported prevalence of 1 in 150. That data was taken in 2002 on 8 year old children. I.e. kids born in 1994. Since reported prevalence numbers are going up with time, it would be very misleading if they were to use, say, prevalence numbers from the early 1990’s, wouldn’t it?

Any prevalence that they use would have to use prevalence numbers from about the same time, on kids of about the same age.

Here’s their table comparing the autism rates.

gr_table3

Let’s take a look at the studies they cited for their numbers, shall we?

Iceland: Prevalence of Autism in Iceland. This 2001 study uses kids from birth years 1984-1993. I.e. most (if not all) of the kids are from the time before the big upsurge in autism diagnoses. Hardly a good comparison to the 2002 CDC study, eh?

For Sweden, they use a paper called, “Is autism more common now than 10 years ago?” from The British Journal of Psychiatry. Published in… 1991. That’s pre DSM-IV. Amongst other problems, they won’t be including the other PDD’s in the autism spectrum, like the CDC study does. Besises, the kids from the CDC study weren’t even born yet, it was so old! Is there any wonder that the Swedish study shows a lower prevalence?

For Japan, they use a paper titled Cumulative incidence and prevalence of childhood autism in children in Japan. The study uses data from 1994 on kids who were born in 1988.

Are you starting to see the pattern here? Time after time, GR is comparing US 2002 prevalence data to much older data from other countries. Let’s go on:

For Norway, they use the paper Autism and related disorders: epidemiological findings in a Norwegian study using ICD-10 diagnostic criteria. The paper was published in 1998 on children 3-14 years of age. Simple math suggests they had kids with birth years going back to at least 1984 in that study. Hardly a good comparison to kids born in 1994.

For Finland, they use Autism in Northern Finland. Here is an updated version from 2005. The study uses data from 1996-97, on kids up to 18 years old. I.e. they are using kids that were born as early as 1979. Also, they are using data on patients from hospital records who used “communal health services”. Sounds a lot like “inpatient”–one of the critiques that GR uses against studies from Denmark. Also, the Finland study didn’t include Aspeger syndrome, as that was a new diagnosis at the time. Hardly a good comparison to the CDC study.

For France, they use Autism and associated medical disorders in a French epidemiological survey. This uses “French children born between 1976 and 1985”.

For Israel, they use Autism in the Haifa area–an epidemiological perspective. This paper looks only at autistic disorder (no PDD-NOS, no Aspergers, no Rett’s no Childhood Degerative Disorder). Right off the bat that reduces the prevalence and makes it impossible to compare the the CDC 2002 study. The Israell study also is, you guessed it, based on kids older than the CDC study: children born between 1989 and 1993.

Last, Denmark. If you’ve been following the thimerosal debate, you know this is going to be ironic. They use Madsen’s paper, Thimerosal and the Occurrence of Autism: Negative Ecological Evidence From Danish Population-Based Data. Generation Rescue refers to this study (incorrectly, I might add) as “This one goes beyond useless”. I guess “useless” is only when it is used to refute the thimerosal hypothesis? Come on, GR, this level of hypocrisy is just painful.

Missing Studies

There are some very well known studies that Generation Rescue somehow forgot to include in their “study”. Could this be due to the fact that they are very good counterexamples to the vaccine-hypothesis ? Let’s look at some and see, shall we?

United Kingdom: Pervasive Developmental Disorders in Preschool Children: Confirmation of High Prevalence ( study performed in 2002 with a prevalence of 1 in 170), and Pervasive developmental disorders in preschool children (study performed in 1998/9 with a prevalence of 1 in 160).

Canada: Pervasive Developmental Disorders in Montreal, Quebec, Canada: Prevalence and Links With Immunizations (birth years 1987 to 1998. Prevalence 1 in 154).

Wow, the United Kingdom and Canada have prevalence numbers comparable to those in the US!

So, let’s complete the comparison, shall we? What is the vaccine schedule like for the UK and Canada? Using the Generation Rescue “study” we get 20 vaccines for Canada and 21 for the UK.

Wow, that’s way less than the US (with 36), and they have the same autism prevalence as the US? How could that be? Is it, perhaps, that the autism is NOT related to the number of vaccines in a given country’s schedule?

Anyone doubt why GR left the UK and Canada off their table of Autism Prevalences Around the Globe? No, I am not giving them a pass that this could be an honest mistake.

To quote Generation Rescue’s top funny guy (Jim Carrey), “How stupid do you think we are?”

It’s different for girls

13 Apr

One of the puzzling things about autism has always been the disparity between the sexes.  Boys have always been more susceptible than girls. This is not in itself unusual. There are gender differences affecting a whole range of conditions and, if this New York Times article is correct, men frequently come off worse.

But if boys are more susceptible you might have assumed that as the severity of the condition increase this disparity would become more marked. In fact you would have assumed wrong. According to this source:

The greater severity and lower frequency of autism in females has been cited as evidence for a multifactorial polygenic mode of inheritance with differential loading by sex, which predicts greater severity in the less frequently affected sex.

Greater severity is usually taken to include severe cognitive impairment as well and the greater the degree of cognitive impairment the closer the ratio between boys and girls.  But there are problems with this model. David Skuse has argued that the association between cognitive impairment and autism is not because they share a common cause but simply because if you have both conditions you are more likely to be seen by a clinician and get a diagnosis. More able people may be just as autistic but have coping strategies that enable them to avoid a diagnosis.  And if girls have better coping strategies than boys they will be disproportionately overrepresented amongst autistic people without cognitive impairment who are missed by the system.

Last week Woman’s Hour broadcast a segment on Asperger syndrome took up this argument and suggested that there may be as many girls as boys on the spectrum. Most of them are not getting a diagnosis because they present in ways that are unfamiliar to clinicians who are used to seeing the condition in boys. The programme is no longer available but Sunday’s Observer carried a two page spread on the same story.

Experts like Judy Gould and Tony Attwood cited by the Observer still believe there is a gender difference but they estimate that it is only 2.5:1. Asperger girls may be more passive than boys. They do not assert their difference or draw attention to themselves. Instead they observe and copy other people’s behaviour. Their special interests may be intense but are also likely to be more socially acceptable; reading fiction, following soaps, celebrity culture – the sort of thing that lots of other girls do – and so they do not stand out.

Conformity comes at a cost. The Observer quotes Tony Attwood’s estimate that 20% of anorexic girls are undiagnosed autistics. Then there is self harm and other evidence of psychological stress. There are important differences between men and women. They need to be understood and respected. But it does not help autistic women if autism is described as an extreme male brain syndrome. The Observer ends by quoting professor David Skuse who believes that:

if we can prove the ratio of boys to girls is as high as many of us suspect, it would be as significant a milestone in this field as the discovery that the condition is on a spectrum.”

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The Somali Minnesotan Autism Epidemic

13 Apr

One of the most intriguing scenarios to pop up from the so-called autism epidemic happened in Minnesota in the US. It was noted that there were what seemed to be disproportionately high numbers of second generation Somali children in Minnesotan schoolrooms. Of course, this was immediately latched on to by the usual suspects, despite the caution issues by health authorities that until proper epidemiological studies had been done it would be impossible to say whether this really was a cluster worth investigation or just a coincidence.

On the 31st March, the Minnesota Dept Health released the study. Its a fairly substantial read. One thing immediately struck me about this:

Administrative prevalence of Somali children, ages 3 and 4, who participated in the MPS ECSE ASD programs was significantly higher than for children of other races or ethnic backgrounds

OK so this is what the families were saying. But there’s an extreme note of caution that should be noted here. This is basically CDDS all over again. Just like some believed that an increasing number of reports to CDDS meant that there was an autism epidemic and just as CDDS said there reports really shouldn’t be used to study these things, MDH are also saying:

Because of the study’s limitations, it is not proof that more Somali children have autism than other children…

This is a vital point. Back in 2005, James Laidler made the clear point that Department of Education data on autism are not reliable for tracking autism prevalence.

Sadly, the new Age of Autism editor, Abdulkadir Khalif, either misunderstood or elected to ignore this issue when he said:

It was obvious from the numbers that the issue of prevalence has finally been settled, and that there definitely is a cluster of autism in Minneapolis

It is clear from the report that Khalif has grossly overstated the case. Firstly, the issue of prevalence is far from settled. MDH seem to be solely using educational data which, as pointed out by Laidler, is not reliable for tracking autism prevalence. Indeed the phrase ‘administrative prevalence’ used by MDH reflects this. ‘Administrative prevalence’ refers solely to numbers of kids in educational programs. This is a clear distinction from ‘prevalence’ which is the proportion of individuals in a population who suffer from a defined disorder. Using only educational data gives a distorted picture.

As has been shown, the USDE data on autism are at odds with studies of autism prevalence, largely because the criteria used by the school districts (the source of the USDE data) to categorize children as autistic are neither rigorous nor consistent. They are inconsistent over time, as are the medical criteria, and are inconsistent from region to region. The USDE data are not reliable for tracking the prevalence of autism, and they in fact never were meant to fill this need.

Secondly Khalif uses the word ‘cluster’ whereas the MDH report does not use it at all. And it is not a word that should be used in such a throwaway fashion – it has a distinct epidemiological meaning.

So clearly, contrary to Khalif’s assertion that the issue of prevalence has been settled, it has not. Contrary to his statement that there is a cluster, there has been no such epidemiological assessment or statement.

Here are some more quotes from the MNH report that Abdulkadir Khalif either chose to ignore or never actually read:

The fact that a child is participating in an ASD early childhood program is an indicator of educational need, but that child may or may not have a medically diagnosed ASD.

Further, Minnesota’s public school open enrollment policy allows children to attend special education programs in school districts where they are not residents. This raised the question of whether participation rates for Somali children might appear higher than the participation rates for non-Somali children because of an influx of Somali children who are not residents of the Minneapolis school district attending MPS ECSE programs for ASD.

Data on variability of ASD prevalence by race, ethnicity, and SES is limited and inconclusive, and apparent differences between racial and ethnic populations may largely be due to differences in case finding and service provision.

Across all assumptions and ASD program types, administrative ASD prevalence estimates for Somali children were uniformly higher than the U.S. parental reported ASD prevalence, but most of the 95% confidence intervals corresponding to the administrative prevalence estimates for Somali children contained the value of the U.S. parental reported ASD prevalence estimate – suggesting that the 2005-2006 administrative ASD prevalence for Somali children might be no different from what would be expected in the U.S. population of children ages 3 and 4 based on parental report.

So what does this mean?

It means that there are no firm answers and that Khalif is simply wrong to assert that there are.

Its always been one of the great puzzles to me that a section of (mostly) parents who demand accurate answers fast cannot seem to understand that there _are_ no accurate answers until the science – proper science – has been done. And that takes time. What legacy do these parents want to leave the autism community? Fast inaccurate mistakes? Or well planned and rigorous science that helps build the growing knowledge we already have?

Is there an autism epidemic – the latest science

25 Mar

A new paper from Eric Fombonne is in electronic print at the journal Pediatric Research. It will apparently be published in the paper version of the journal some time after April.

The title is ‘Epidemiology of pervasive developmental disorders’ and as the name suggests, Fombonne looks at all the available quality epidemiology he can find relating to PDD’s.

This article reviews the results of 43 studies published since 1966 that provided estimates for the prevalence of Pervasive Developmental Disorders, including Autistic Disorder, Asperger Disorder, Pervasive Developmental Disorder Not Otherwise Specified, and Childhood Disintegrative Disorder.

Combining all these categories together Fombonne presents a prevalence of 60-70/10,000.

For autistic disorder, Fombonne says:

The correlation between prevalence and year of publication was statistically significant and studies with prevalence
over 7/10,000 were all published since 1987. These findings point towards an increase in prevalence estimates in the last 15-20 years.

For PDD-NOS, Fombonne explains that it is next to impossible to get accurate prevalence rates as:

This group has been much less studied in previous epidemiological studies…

Again, for Aspergers, Fombonne says that AS specific epidemiological studies are sparse but, in something of a surprise:

By contrast, other recent autism surveys have consistently identified smaller numbers of children with AS than those with autism within the same survey. In 9 out of 10 such surveys, the ratio of autism to AS prevalence in each survey was above unity, suggesting that the prevalence of AS was consistently lower than that for autism. How much lower is difficult to establish from existing data, but a ratio of 3 or 4 to 1 would appear an acceptable, albeit conservative, conclusion based on this limited available evidence. This translates into a prevalence proportion for AS which would be ? to ¼ that of autism. We therefore used for subsequent calculations an estimate of 6/10,000 for AS, recognizing the strong limitations of available data on AS.

Lastly, for CDD:

Eight studies provided data on childhood disintegrative disorder (CDD). Prevalence estimates ranged from 0 to 9.2/100,000. The pooled estimate based on eight identified cases and a total surveyed population of 406,660 children, was 2.0/100,000. The upper-bound limit of the associated confidence interval (4.0/100,000) indicates that CDD is a very rare condition, with about 1 case to occur for every 103 cases of autistic disorder.

Fombonne then tackles the question everyone wants an answer to – is there an autism epidemic?

In order to answer this accurately, he explains that there has to be tight control over incidence estimates (the number of new cases occurring in a population over a period of time) and prevalence (the proportion of individuals in a population who suffer from a defined disorder). Failure to control these gives false results. Bearing this in mind, Fombonne goes through the five approaches taken so far to try and determine if theres an autism epidemic or not.

1) Referral Statistics.
Trends in time for referral statistics are not reliable. They fail to control for things such as referral patterns, availability of services, heightened public awareness, decreasing age at diagnosis and changes over time in diagnostic concepts and practices. An example of the issues from referral statistics is:

Strong evidence of “diagnostic switching” was produced in California and in all US states indicating that a relatively high proportion of children previously diagnosed as having mental retardation were now identified as having a PDD diagnosis. Decreased age at diagnosis has also been shown to contribute to the rising numbers of children diagnosed with PDD. In the UK, Jick and Kaye (62) have shown that the incidence of specific developmental disorders (including language disorders) decreased by about the same amount that the incidence of diagnoses of autism increased in boys born from 1990-1997. A more recent UK study has shown that up to 66% of adults previously diagnosed with developmental language disorders would meet diagnostic criteria for a broad definition of PDD.

2) Comparison of cross-sectional epidemiological surveys
If I’m understanding his point here (and please correct me if I’m not) Fombonne is saying that too many epidemiological studies are uniquely designed – not enough attempt to replicate a previous study – and hence:

The most convincing evidence that method factors could account for most of the variability in published prevalence estimates comes from a direct comparison of 8 recent surveys conducted in the UK and the USA. In each country, 4 surveys were conducted around the same year and with similar age groups. As there is no reason to expect huge between-area differences in prevalence, prevalence estimates should therefore be comparable within each country. However, there was a six-fold variation in prevalence for UK surveys, and a fourteen-fold variation in US figures. In each set of studies, high estimates derived from surveys where intensive population-based screening techniques were employed whereas lower prevalence proportions were obtained from studies relying on passive administrative methods for case finding. Since no passage of time was involved, the magnitude of these gradients in prevalence can only be attributed to differences in case identification methods across surveys.

3) Repeat surveys in defined geographical areas
So this is the opposite of the above – these are studies where they are being replicated as closely as is possible. However, the issue here is that there are simply not _enough_ of these studies to form a definite conclusion. However, it may be worth noting that in the two studies Fombonne highlighted as being carried out in exactly the same way in exactly the same place to exactly the same age cohort – but just at two different times one showed no increase in prevalence whilst the other showed no increase at 4 sites and an increase at 2 sites.

4) Successive birth cohorts
This means in very large surveys with a wide age range, if the proportion of people who have autism rises this _could_ be a rise in incidence and therefore a good hint that there is an epidemic. I say _could_ as other possible causes need to be ruled out first.

…two large French surveys [used this method]. The surveys included birth cohorts from 1972 to 1985…, and, pooling the data of both surveys, age-specific prevalence showed no upward trend.

A US survey _did_ show an upward trend but:

…the increase was not specific to autism. These analyses also showed a marked period effect that identified the early 1990s as the period where the prevalence estimates started to go up in all ages and birth cohorts, coinciding closely with the inclusion of PDDs in the federal Individual with Disabilities Educational Act (IDEA) funding and reporting mechanism in the US.

5) Incidence studies
The few incidence studies did show incidence trends rising over short periods of time. As noted in point 4) above, this _could_ be attributed to an autism epidemic. However –

…none of these studies investigations could determine the impact of changes over time in diagnostic criteria, improved awareness and service availability on the upward trend.

Contrary to what people who _want_ there to be an autism epidemic, these are non trivial reasons. It stands to reason that if (for example) Birmingham, UK – the countrys second city, goes from having zero service availability and no means of diagnosis in 1960 to having numerous types of service availability both publicly and privately funded and a _lot_ of means of diagnosis in 2000 there will be a _lot_ more autistic people in Birmingham. A hell of a lot. When we then consider that the diagnosis criteria has widened massively than we go from a hell of a lot more autistic people to a _whole hell_ of a lot. If we _also_ consider that people who used to carry one kind of diagnosis are now being swapped to autism then we go from a whole hell of a lot to a descriptive term beyond my ability. This isn’t even science – its basic common sense. The only issue is – ‘a whole hell of a lot’ is not a very accurate measurement.

Fombonne closes by saying that – based on the available data – we still cannot really say one way or the other if there has been an autism epidemic. Remember when you read the quote below that its _incidence_ that gives us an epidemic.

Current evidence does not strongly support the hypothesis of a secular increase in the incidence of autism but power to
detect time trends is seriously limited in existing datasets. Whilst it is clear that prevalence estimates have gone up over time, this increase most likely represents changes in the concepts, definitions, service availability and awareness of autistic-spectrum disorders in both the lay and professional public. To assess whether or not the incidence has increased, method factors that account for an important proportion of the variability in prevalence must be tightly controlled. The possibility that a true change in the underlying incidence has contributed to higher prevalence figures remains, however, to be adequately tested.

New thimerosal study, altogether now…

26 Jan

…there’s still no link.

‘Neuropsychological Performance 10 Years After Immunization in Infancy With Thimerosal-Containing Vaccines‘ is a new study from Italy.

Nearly 70% of the invited subjects participated in the neuropsychological assessment (N = 1403). Among the 24 neuropsychological outcomes that were evaluated, only 2 were significantly associated with thimerosal exposure. Girls with higher thimerosal intake had lower mean scores in the finger-tapping test with the dominant hand and in the Boston Naming Test.

And here’s the conclusion from the penultimate page of the paper (excluding references):

No study conducted to date has been able to provide conclusive evidence of an effect of thimerosal on neuropsychological development. Final judgments regarding this association must rely on the entire body of results from studies conducted in different settings and with different levels of validity and on the coherence of results. The lack of consistency among the results of our study and other available studies suggests that an association between thimerosal exposure through vaccination in infancy and neuropsychological deficits is unlikely or clinically negligible. Additional data from populations with wider ranges of
exposure to thimerosal and additional neuropsychological assessments at older ages may help to clarify the issue of potential associations between thimerosal and neurodevelopmental outcomes.

Oh, and for the conspiracy theorists:

The authors have indicated they have no financial relationships relevant to this article to disclose.

I’m not an epidemiologist so I’m not going to attempt to go through the nuts and bolts of this paper. Hopefully those who have more expertise can go through yet again why this shows that thimerosal in vaccines seems to be about as dangerous as the average housefly. I can’t imagine they really want to. God knows I don’t. But the stupidniks will no doubt need the finer points hammered home again.

Can you sense I’m getting bored with this yet?

Parental age is a 'risk factor' for autism

15 Dec

A story today talks about how parental age _may_ be a ‘risk factor’ (loaded phrase much?) for autism. According to the studies lead author (Dr. Maureen Durkin of the University of Wisconsin School of Medicine and Public Health):

What we found was that actually it’s both parents age, and when you control for one parent’s age you still see the effect of the other parent’s age, and vice versa,

….

After the researchers accounted for factors that might influence the results, they found that children born to mothers aged 35 and older were 30 percent more likely than those whose mothers were 25 to 29 years old to have been diagnosed with autism. Having a father who was 40 or older boosted risk by 40 percent.

The study didn’t really look at why this might be but they did do a bit of educated blueskying:

Older parents have had a longer time to sustain genetic damage to their sperm or egg cells, as well as to store up environmental contaminants in their bodies.

They are also more likely to have used assisted reproduction technologies, which have been tied to poor pregnancy outcomes. And there could be something about the behavioral traits or psychological makeup of people who wait to have children that boosts autism risk in their offspring.

Which is all a fancy way of saying: I got nuthin’ so here’s an answer that covers everything. Which is fair enough, it falls totally outside the remit of the paper to answer those questions.

So now you can expect a whole bunch of people to cast aspersions on this study, relating how really they were only 19 when they had an autistic kid and that its all a big conspiracy to detract from the evil vaccines. Whatever.

Its quite an interesting study, the most recent of many that look at (and find a connection) between parental age and autism. Does it move us forward in terms of causation? Nope. Does that really matter? Nope. Its still nice though to see science being done that is just that most important of work – the hog work that starts to fill in the blanks of the most basic facts surrounding an issue. Thanks to this study and those preceding it I think its fair to say now that raised parental age is a factor in autism causation. Not always but sometimes.

Another interesting bit of blueskying:

The findings could also help explain why autism appears to be on the rise in the United States, the researchers added, since the percentage of children who are born to mothers 35 and older and fathers 40 and older has risen steadily since 1980.

I think this is a very interesting hypothesis to follow up on and I hope someone does. But first of all of course we need to establish _if_ autism is ‘on the rise’. Many people will tell you there’s an epidemic of autism but there is in fact no valid evidence to support this supposition. I hope some evidence can be forthcoming. We need it.

Evidence of Autism in a Psychiatrically Hospitalized Sample

4 Nov

I’ve been meaning to write something on this for a while. This was a talk given at IMFAR this year (2008) by one of my favorite research groups–that of Prof. David Mandell. If you’ve listened in on IACC meetings you’ve heard him. Much more, if you have been watching the literature, you’ve likely seen his papers.

Prof. Mandell asks a lot of questions that I think are important and, all to often, overlooked. As an example, he has documented the late diagnoses of ASD’s in ethnic minorities in the United States.

One presentation at IMFAR that caught my eye was:

Evidence of Autism in a Psychiatrically Hospitalized Sample

The abstract is quoted below:

L. J. Lawer , Psychiatry, University of Pennsylvania, Philadelphia, PA
E. S. Brodkin , Psychiatry, University of Pennsylvania, Philadelphia, PA
D. S. Mandell , Psychiatry, University of Pennsylvania, Philadelphia, PA

Background: The similarity of the symptoms of ASD with other psychiatric disorders, and the fact that misdiagnosis may lead to inappropriate treatment, has led to interest in the prevalence of ASD in psychiatric populations. The four studies in this area have estimated the prevalence of ASD in adult psychiatric samples to be between 0.6% and 5.3%.

Objectives: To determine the potential prevalence of ASD among psychiatric inpatients and characteristics that discriminate between adults likely to have ASD and other psychiatric disorders.

Methods: The sample included 350 out of 396 patients in one state psychiatric hospital in Pennsylvania. Nursing staff completed the Social Responsiveness Scale (SRS) for each subject. Chart reviews were conducted to examine functioning and medical history. T-tests and chi-square tests were used to examine differences in clinical presentation, putative diagnoses, and medical history among patients scoring above 100 on the SRS (a score highly specific for autistic disorder in the general population) and patients scoring below 100.

Results: Twenty-one percent of patients received an SRS score over 100. They were significantly more likely than other patients to be diagnosed with undifferentiated schizophrenia (30% vs. 22%) and have indication in their charts of childhood onset or a “long history” of psychiatric problems (68% vs. 50%), not starting high school (20% vs. 8%), abnormal movements (20% vs. 10%), gastro-intestinal problems (34% vs. 23%), and mental retardation (15% vs. 5%). Analyses of differences in medication use and self-injurious behaviors are ongoing.

Conclusions:While not conclusive regarding the prevalence of ASD in a psychiatric inpatient sample, these findings are provocative and suggest the need for further research. We currently are conducting patient and family interviews to augment existing data. Improved diagnostic assessment for adults with ASD, especially those that discriminate ASD from the negative symptoms of schizophrenia, may have important treatment implications.

The majority of the overall population had schizophrenia diagnoses (80%), with personality disorder, substance abuse and mental retardation diagnoses also present.

The researchers had nurses test inpatients using the Social Responsiveness Scale (SRS), and found that a significant number (21%) of the inpatients scored in a range indicating an ASD.

3% of those with SRS scores >100 had an existing ASD diagnosis. Compare that to 1% of those with scores <100 on the SRS. But, you can see that with 21%, this inpatient population had a much higher autism rate than the roughly 1% expected for the general population.

Interestingly, there was a higher rate of GI problems in those with high SRS scores.

The ages? These are adults. Not just young adults, either. They ranged in age from 20-82, with an average of 49 (SD of 13) years.

Why is this important? There are many reasons. First, before this study was presented at IMFAR, the results were referenced by one of the world’s top-cited autism researchers, Nancy Minshew, in a news article.

The other phenomenon was that some autistic children were labeled as schizophrenic, and many may have ended up in state hospitals or other institutions, she said.

There is even a kind of logic to that, Dr. Minshew said, because some of the hallmarks of schizophrenia — behaving oddly, a lack of facial expressions, poor eye contact, speaking in a monotone and using fewer gestures than normal — are “essentially the same” in both autism and schizophrenia.

David Mandell, an epidemiologist at the University of Pennsylvania medical school, recently surveyed the adult patients in Norristown State Hospital in Eastern Pennsylvania, nearly all of whom are labeled schizophrenic, and found that about 20 percent of them meet the behavioral criteria for being autistic.

The response? Dr. Minshew was openly mocked by “advocates” who apparently couldn’t see past the fact that these results pose a challenge to the “epidemic”. Kim Stagliano, in a Huffington Post Piece, was annoyed that Dr. Minshew would say that in her experience there is “not an increase in the number of cases, but are an improvement in recognition.” On the age of autism blog, Ms. Stagliano went on to say,

Does your child, or do you (if you are an adult with autism) appear schizophrenic*? Has any doctor or therapist ever uttered the words schizophrenia and autism in the same sentence to you?

This declaration of Dr. Minshew’s is repulsive and offensive to all people with autism. All people with autism, regardless of what you think of cause or treatment.

Amongst the mistakes Ms. Stagliano makes in the above is asking the wrong question. The question is not “do people with autism appear schizophrenic”, but, rather, do people with schizophrenia (and other) deserve diagnoses have autism? Further, are these people misdiagnosed or do they deserve autism in addition to their other diagnoses?

Ms. Stagliano isn’t the only one to attack Dr. Minshew’s statements without thinking them through (Dr. Minshew’s statements made it clear that she was basing her statements on actual studies, not just her opinion). I’d like to point out that I didn’t bring Ms. Stagliano’s comments in as a mere sidetrack. Much as the comments annoyed me, they point to a more important, systematic problem: The “advocates” of the past 10 years have made a big mistake in concentrating solely on children with autism.

First and foremost, it is wrong to the allow fellow citizens to go without proper supports. This is especially true if (as noted in the talk) there is the possibility of de-institutionalizing these people. We must insure that these adults and those who will care for them have a proper understanding of the real issues each adult faces.

Second, it is just plain short-sighted. For parents of children with autism, autistic adults are the great untapped resource. We have much to learn, much that will help our children. It is in our own self-interest to demand that adults with autism be identified so we can learn from their hard-fought lessons.

I don’t know a better way to emphasize this than to restate it: It is in our own self-interest to demand that adults with autism be identified so we can learn from their hard-fought lessons.

[note: I edited this piece for clarity and emphasis after posting. The substance was not changed]

Every Child By Two: Oprah, Jenny McCarthy et al

20 Oct

An email from Amy Pisani – a thoroughly charming lady who runs the organisation Every Child By Two – made me nod appreciatively today. I’ll quote it in full:

It has been quite some time since Every Child By Two (ECBT) has asked you to take action on an issue related to immunizations. I write to you today with an urgent request for your assistance in reaching out to the Oprah Winfrey Show to urge that she dedicate a show to the science behind the question of whether vaccines cause autism.

More than fourteen credible studies have been conducted worldwide exonerating vaccines and yet the media and entertainment industry continue to frame this as a debate. ECBT and our public health partners have reached out to Oprah’s producers countless times without success. However, I recently had a lengthy conversation with one of the producers who recommended that we initiate a letter writing campaign by commenting within the Oprah.com feedback section of the website. This information is tabulated to determine whether there is enough interest to conduct follow up shows.

I urge you to take five minutes to fill out the Oprah Winfrey Show online form by following the link below. In your comments, please request that Oprah invite credible scientists and/or physicians to explain the science of vaccines to her viewers. We also would like her to invite parents who have suffered the loss of a child from a vaccine-preventable disease, and a parent of an autistic child who can speak on behalf of the many families that are frustrated over the continued focus on vaccines and their supposed link to autism and the therapies that focus on “repairing vaccine damage”. Please relate any personal experiences you may have with vaccine-preventable diseases or autism. In addition, please refer the Oprah Winfrey Show to Amy Pisani, Executive Director of Every Child By Two, for any follow-up questions.

And finally, please forward this to your family and friends and request that they also reach out to the Oprah Winfrey Show.

https://www.oprah.com/ord/plugform.jsp?plugId=215

An excellent idea. I’d like to see a show that mirrors the one sided show that Jenny McCarthy recently got – the one where she was free to spout off her latest game of ‘cure the Evan‘ (he’s cured, no he’s not, yes he is….) but this time with a careful step by step walk through the science that:

…is largely complete. Ten epidemiological studies [plus two clinical ones and the testimony of Stephen Bustin] have shown MMR doesn’t cause autism; six have shown thimerosal doesn’t cause autism; three have shown thimerosal doesn’t cause subtle neurological problems; a growing body of evidence now points to the genes that are linked to autism; and despite the removal of thimerosal from vaccines in 2001 [and the 10% drop in MMR uptake between 1997-2007], the number of children with continues to rise.

– Autism’s False Prophets, Page 247. Dr Paul Offit.

Compare this hard, clinical, transparent (and thus independent) science with Mother Warrior Jenny McCarthy’s recent evangelical call to arms:

“I made a deal with God,” she explains. “I said, ‘You fix my boy, you show me the way and I’ll teach the world how I did it.'”

Hallelujah! Or whatever. To misquote the Pythons – she’s not the Messiah, she’s just a very silly girl.

Please act on Amy Pisani’s request – do it right now.

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