Addressing the ‘too many too soon’ hypothesis

3 Jun

Regular readers may be aware that I blogged about a study recently that demonstrated the early stages of tackling the ‘too many too soon’ hypothesis. It came in for some fierce criticism in the comment section so I wrote to the lead author to get his thoughts. What follows is his answer to me via email:

Reviewing your blog, there are two related criticisms of our study.

First, I must clarify the conflict of interest comment. Though less relevant in my mind, it addresses the other limitations noted by your readers. This study was completely unfunded – not by any pharmaceutical company, not by the CDC. We did this all in our free time because of a simple non-financial “conflict” – as infectious disease physicians we take care of children who suffer needlessly from vaccine preventable diseases. This clarification of funding leads to point 2 – because we
did not have millions of dollars at our disposal we chose to use pre-existing data to address a common parental concern for which we could not find any evidence-based talking points.

This strategy had significant benefits – once we had the idea for this study we got right to work and did not have to wait 7-10 years to see what the outcomes might be. However, as we acknowledge in the discussion (and your readers point out), the use of pre-existing data also introduces limitations. We did not have control over which outcomes were tested, nor which children were included or excluded from the original study.

Nevertheless, I believe this study was accepted for publication in an academic medical journal because it offers a unique methodology that may be used to study the effects of delayed vaccination on any outcome of choice, whether it be the incidence of vaccine-preventable diseases or the proposed vaccine side effect du jour. Unfortunately, I do not have the resources to perform these studies myself.

A separate question – which is really a critique of the original NEJM study (with which I was not involved) and not ours per se – is why the authors chose to exclude the children they did. In the time since you e-mailed be I believe “Luna_the_cat” has explained this fairly clearly. Basically, the original study excluded children with brain injuries that would not have been related to vaccination (except for a few – pneumococcal and haemophilus influenza meningitis which vaccines PREVENT) and this seemed reasonable in the initial study. Furthermore, the majority of these exclusion criteria are prenatal or congenital diagnoses that would have predated vaccination anyway.

Finally, regarding lack of “controls”. This was not a “vaccinated versus unvaccinated” study, nor was it intended to be. It was designed to address the “too many too soon” hypothesis. Our “controls” were those children in the cohort who received fewer vaccines later during the first year of life. In this case the “exposure” was timely vaccine receipt – which was never associated with any adverse neurodevelopmental outcomes.

It is free speech, but is it appropriate behavior?

2 Jun

A good friend sent me a link to a recent story in the Los Angeles Times, Housewife awarded $110,000 after alleging government infringed on her free speech rights. At first glance I was wondering, why send this to me? Then I read the story:

A Norco housewife whose protests against a group home for the developmentally disabled drew the scrutiny of housing discrimination investigators, has settled a lawsuit alleging the government inquiry infringed on her right to free speech.

Julie Waltz, 64, agreed this month to settle her case in exchange for $110,000 and the promise that the California Department of Fair Employment and Housing will establish a “Julie Waltz First Amendment Policy.”

Yes, Ms. Waltz protested a group home and, it appears, the government acted inappropriately in response. She sued, the government settled, and she got a nice big check. I am a firm believer in the first amendment, even when it is used by people taking positions I abhor.

But–I will also state that every right comes with a responsibility. The Freedom of Speech, the First Amendment, comes with a very serious responsibilities. If I were to exercise my freedom of speech, I would state that Ms. Waltz has acted inappropriately and irresponsibly. She has skirted the laws and victimized the disabled.

Ms. Waltz, as you might imagine, disagrees:

In an interview this week, Waltz said, “I wouldn’t say my speech is offensive, but even if it is, the very speech someone says is offensive is the speech we need to protect.”

Offensive speech is not the only speech we need to protect. Speech by the disadvantaged, the weak, that needs to be protected as well.

After reading the LA Times story, I went through the news archives for stories about Ms. Waltz. What I found was not pretty.

Ms. Waltz has taken on a 6 year campaign against a group home next door to her own home. In 2004, when Ms. Waltz read the mission statement for the then proposed home, she keyed in on two statements. The residents might include people with “physical aggression” and/or “sexual inappropriateness” and “fire setting”.

Armed with this, Ms. Waltz led a neighborhood campaign which sewed fear “rape” and “violence” should the group home be opened. She has continued this campaign long after the home has opened.

Here are clips from a story in 2004, where it is clear that the atmosphere in the neighborhood was decidedly antagonistic:

Gary Durham, whose home on Bluff Street has been for sale for nearly two months, said he doesn’t see a peaceful resolution for the community.

People have been knocking over the mailbox and doing doughnuts on the front lawn of the group home, he said.

“The situation is escalating,” he said. “I don’t think the (group home) residents will ever be safe walking out their front door in this neighborhood. They have no idea what they’ve gotten into here. I just wish I could sell my home and get out of here.”

(for anyone who wonders: “doing donuts” means driving a car in tight circles very fast, tearing up the lawn).

Ms. Waltz showed a lack of compassion for the members of the group home:

“We have the right to be heard,” Waltz said. “No one will help us because they think we’re bigots, but I’m tired of being called a bigot just because I care about my neighborhood.”

Waltz said she’s not bothered that some of the signs that have gone up in the neighborhood are menacing in tone. Some have said, “Freaks get out,” “Rednecks unite” and “Safe living. Relocate.”

“If they feel threatened, they know how we feel,” she said. “If they don’t feel like this is a safe neighborhood for their clients, maybe they shouldn’t open a home here.

The comment appears to this reader to be a major sidestep by Ms. Waltz. Rather that accept responsibility for her actions, she has put the blame on the group home residents.

Another story from that time points to the fear mongering used in the campaign against the group home:

The signs along Broken Arrow Street speak loudly: “Your wife & kids are potential rape victims thanks to the government” and “Do you feel safe? We don’t.”

and

The signs include such slogans as “No more! Liar Group Homes” and “Pedophiles, rapists & molesters all display sexual-inappropriateness.”

Note the clever use of language. “Pedophiles, rapists & molesters all display sexual inappropriateness”. They don’t call the group home members “rapists” or “pedophiles” or “molesters” directly. But who is really fooled as to what the message they are trying to convey is?

From another story in 2004:

At times, the fear has given way to hostility and violence, with unknown vandals throwing bricks through the planned group home’s windows, tearing up the lawn, running over a mailbox and snaking a running garden hose through a roof-top opening, which caused the collapse of a ceiling.

Employees and people delivering appliances to the planned group home have been threatened, and neighbors have hoisted dozens of protest signs – some with such strongly worded slogans as “Those people are violent – goes both ways” and “Freaks get out.”

In 2005, the garage door to the home was vandalized with a swastika and the words “get out now”.

During the night Friday, someone threw eggs at the home and vandalized it with a magic marker, sheriff’s officials said. Last summer, the same home had its lawn and mailbox damaged.

A story from 2007 discusses Ms. Waltz again, this time from the perspective of her free speech rights. Ms. Waltz is shown in that story standing proudly next to the signs on her lawn stating “Sexual Inappropriate Fire Setter Facility” and “I.R.C. Does Place Sex Offenders”. (I.R.C. is the Inland Regional Center, which administers services for the developmentally disabled for the California Department of Developmental Services)

Every right comes with responsibility. Freedom of speech comes with a heavy responsibility. Ms. Waltz is exercising her free speech rights. She is staying within the law by not directly claiming that the women in the group home are “sex offenders” or that they are “fire setters”. Again, the language is carefully chosen. It skirts the law and delivers the message at the same time.

To this reader’s eye, she is acting very irresponsibly in her choice of words. She is, in my view, creating an environment of hostility and fear.

In 2007, residents were still afraid for the market value of their homes. Some were having problems selling their homes:

The same campaign that drove the group home out is driving potential buyers away, said Leslie Anderson, whose own home on Bluff Street has been on the market for weeks.

“The situation over there has gotten out of hand,” Anderson said. “I finally got a tentative offer, but it was withdrawn when they drove down Broken Arrow and saw all the signs.”

Anderson said her real estate agent was verbally accosted by Broken Arrow residents because they didn’t recognize her car.

Ask yourself this: did the neighborhood residents think that the real estate agent was a resident of the group home? Obviously not. Were people put off by the group home or, as the resident put it, the signs?

If there is devaluation of the home prices in that neighborhood, the residents need to shoulder their own share of the responsibility.

Next to her American and Confederate flags, Waltz has plastered the outside of her house with signs protesting the group home.

Flying the Confederate flag is protected by free speech laws. But, let’s face it: the Confederacy was fighting to protect their rights to enslave African Americans. For many in the United States, the Confederate Flag is a form of hate speech. Ms. Waltz does not exactly give herself credibility by flying that flag.

Can the residents really expect to push the group home out? It turns out that this group home was not the first planned for this neighborhood. Another 2004 story discusses how a group home was relocated after the residents’ reaction went as far as vandalism:

The owners of a group home for the mentally disabled have decided not to open in Norco for fear that their clients would suffer abuse from an openly hostile community, company officials said Thursday.

Officials with Marjan Homes Inc. said they no longer feel safe opening a home for four mentally disabled adults on Broken Arrow Street after employees reported being threatened by neighbors and after the vacant facility was twice vandalized, said City Manager Jeff Allred.

Keep that in mind when you read this next clip. This is from the LA Times in 2007, when Ms. Waltz brought her freedom of speech complaint forward:

Over Waltz’s objections, the home received state funds to open in 2005. Waltz said that when her new neighbors arrived, they hurled rocks and obscenities at her. She and some neighbors then placed signs in their yards urging the group home to “get out” and warned neighbors that “your wife and kids are potential rape victims” — driving the residents inside to tears, according to their advocates.

“She and some neighbors then placed signs…” Ms. Waltz makes it seem like it was only after the group home was opened and the members acted inappropriately that the protests started. She conveniently leaves out the vandalism and hatred that kept one home from opening. She conveniently leaves out the actions of her neighborhood–intimidation and vandalism–before the present group home opened.

There are good, honorable people who have fought to protect the freedom of speech in the United States. Julie Waltz, proud of her victory, is not one of those people.

Blocking immunisation

2 Jun

The rise of a public anti-vaccine movement in the US is partly to blame for blocking effective immunisations according to the AAP today.

A story on WebMD says that the

…rise of a public anti-vaccination movement that uses the Internet as well as standard media outlets to promote its position, which is “wholly unsupported by any scientific evidence” linking vaccines with autism and other childhood conditions.

is at least partly to blame for ensuring that ‘pockets’ of unimmunised children exist throughout the US. Other reasons given include problems with cost.

Read the whole story at Web MD (@WebMd).

AutismOne Generation Rescue conference expells registered attendees

2 Jun

Autism News Beat has this story in full in Listening to parents at AutismOne. AutismOne is a parent convention with a major focus on alternative medicine. To put them in perspective, Jenny McCarthy is a frequent keynote speaker and Andrew Wakefield was honored by AutismOne last year after it was revealed that his study was possibly tainted by misreporting of results.

If you recall, AutismNewsBeat was expelled from a previous AutismOne conference. He had just asked, respectfully, an important question of Hannah Poling’s mother (Hannah Poling is the child whose case before the vaccine court was conceded on the basis of vaccines aggravating an underlying mitochondrial disorder). To my knowledge, AutismNewsBeat has no been given a clear reason for the expulsion.

A filmmaker/Journalist was present at this year’s AutismOne. Lars Ullberg had applied for press credentials and was denied. AutismOne responded to this request stating:

Autism One is not prepared to offer press passes to you or your crew. Although you and each of your crew members may pay the registration fee as regular attendees, subject to the usual terms of attendance, neither you nor your crew members are permitted to conduct any videography, photography, audio recording, or press interviews; furthermore neither you nor your crew members are permitted to quote attendees, presenters, exhibitors, volunteers, or staff in any manner that will be quoted, “on the record,” or used for public or private media or instructional purposes. Additionally, you and your crew members must identify yourselves accurately with your affiliations to those to whom you speak and also not mislead them to think that you are simply seeking information with which to help your child. Finally, you may not eavesdrop on private conversations between attendees. In summary, Autism One grants no permission to you or your crew to report on this conference or its attendees. Should we become aware that you are not following these guidelines, we will not hesitate to ask you to leave the conference.

AutismNewsBeat asked AutismOne for details on why Mr. Ullberg was removed from the conference, but he has yet to receive a response.

I find the wording and possible intent of this sentence rather odd: ” Autism One grants no permission to you or your crew to report on this conference or its attendees”. If an attendee chose to be interviewed, would that not be OK? The conference appears to be speaking for its attendees.

In addition, a public health official was in attendance for this year’s AutismOne conference. This person also was asked to leave. According to AutismNewsBeat:

A staff member of a western state department of public health was reportedly attending a session on vaccines and parental rights. According to one source, the speaker was advising parents how to apply for and receive vaccine exemptions. The session was interrupted by an AutismOne organizer who commandeered a microphone to announce that a state health department staff member was present, so parents should be careful about what was discussed.

A short time later four Westin O’Hare security guards entered the room, identified the staffer, and directed her to leave the conference facility.

Perhaps in the case of the journalist, AutismOne was afraid of bad press. But haven’t parent groups been asking for some time for people to listen to them? A public health official attends the conference in order to listen and is expelled.

Generation Rescue and Autism One appear to be working in a very defensive, entrenched mode. Internet chatter is mentioning closed sessions where Andrew Wakefield spoke. Closed sessions? Expelling journalists? Refusing permission for journalists to report on what attendees have to say–even if the journalist clearly identifies himself? Asking public health officials to leave for no apparent reason? Again, this comes across to me as an entrenched, defensive mindset.

Andrew Wakefield – as succesful an author as researcher

2 Jun

Andrew Wakefields supporters were hoping his new book would be a bestseller. That ain’t going to happen given how much a publishing insider revealed to me how many he has actually sold:

He sold a total of 1017 copies. Top sales 157 copies in NYC. 46 in LA, 43 in Atlanta (perhaps CDC people wanted to see what he said?!), 38 in Boston, 24 in Chicago, 18 in Seatlle and 17 copies in his hometown of Austin

Ouch. It’ll be interesting to see how well the book does as interest in it fades. Or maybe ‘well’ isn’t the right word.

Another Wakefield paper retracted

1 Jun

Following the retraction by The Lancet of Mr. Wakefield’s “landmark” 1998 paper, many speculated as to if and when other retractions would follow.

The patient pool Mr. Wakefield relied upon for his study was very biased by the referral process. Also, Mr. Wakefield’s team was working without ethical approval for many of the children studied. The natural question to follow is not if The Lancet should retract, but how many papers by Mr. Wakefield’s team were also tainted and should be retracted.

The American Journal of Gastroenterology has retracted a paper from 2000 by Mr. Wakefield’s team: Enterocolitis in Children With Developmental Disorders.

Here is the notice:

Retraction: Enterocolitis in Children With Developmental Disorders

A J Wakefield, A Anthony, S H Murch, M Thomson, S M Montgomery, S Davies, J J O’Leary, M Berelowitz and J A Walker-Smith

Am J Gastroenterol 2000; 95:2285–2295

On 28 January 2010, the UK General Medical Council’s Fitness to Practice Panel raised concerns about a paper published in the Lancet by Dr Wakefield et al. (1). The main issues were that the patient sample collected was likely to be biased and that the statement in the paper, that the study had local ethics committee approval, was false. There was also the possibility of a serious conflict of interest in the interpretation of the data. The Lancet has now retracted this paper (1). This paper in the American Journal of Gastroenterology (AJG) (2) also includes the 12 patients in the original Lancet article and therefore we retract this AJG paper from the public record.

Science based autism charities?

1 Jun

Science Based Medicine is a blog devoted to, well, discussing science based medicine. The subject of autism comes up fairly regularly, usually in the context of the vaccine/autism discussion. A recent SBM piece by Dr. David Gorski, Nine differences between “us and them,” nine straw men burning, caught my eye.

Dr. Gorski comments:

Alison Singer (@alisonsinger), President of the Autism Science Foundation, arguably the only truly science-based autism charity in existence at the moment,

I was about to write a comment when I decided that a blog post was more in order.

The Autism Science Foundation is a science-based autism charity. But, is it really arguable that there are no other truly science-based autism charities?

The answer (as you can likely guess) is “no”. Two names come to mind readily, but I don’t suggest this is an exhaustive list.

[Correction–it has been pointed out to me that both the foundations below do not accept public donations. Thus, they are not “charities”. That would leave the Autism Science Foundation as the one major science based charity]

Who is the largest autism charity? A lot depends on how you define size, but let’s just consider money. Who has the most and who spends the most? If you are thinking Autism Speaks, you are incorrect. The answer is the Simons Foundation.

The Simons Foundation has two main focuses, Math&Science and Autism. They run one of the better blogs on autism science. One of the recent members added to the Interagency Autism Coordinating Committee is from Simons. Most of the autism charities you might know of are working on the basis of taking money in and turning around and spending that money. That is part of the reason why you know about them, they have to keep their name in the public’s eye to get donations. Simons works from an endowment, a foundation. A big one. As of 2008, Simons had assets worth over US$1 billion ($1.108B if you want details). From this endowment, they fund research. After the U.S. Government, they are likely the largest source of autism research funding in the world.

If you check the Simons Foundation website and blog, you will see a decidedly science oriented organization.

The Nancy Laurie Marks Foundation also supports a number of science projects, as well as some advocacy efforts. The Nancy Laurie Marks Foundation was working from an endowment of nearly $US90 million in 2008.

I will highlight two paragraphs from the Marks Foundation “about” page:

The principal goal of the scientific program is to achieve a deeper understanding of the biological basis of autism, focusing on genetics, synaptic chemistry, the neurobiology of communication, systems biology and the physiology of movement. The Foundation funds peer-reviewed research, the development of collaborative investigator projects, and research fellowship programs. Through sponsorship of scientific conferences, symposia and workshops, the Foundation seeks to encourage innovation and provide a springboard to generate new avenues of shared inquiry.

and

The NLM Family Foundation actively seeks partnerships with other grantmakers sharing its goals and fosters collaborations between investigators and organizations that have a direct interest in developmental disabilities. Of particular interest are projects which challenge stereotypes that stand in the way of people with autism realizing their potential, such as the misconception that people with autism are invariably mentally retarded and have minimal interest in social interaction. Challenging such stereotypes will lead to a greater public understanding of autism and widen the scope of scientific inquiry.

The Nancy Laurie Marks Foundation recently donated US$29 million to Massachusetts General Hospital to start a program focusing on the needs of autistic adults.

I am regularly taken to task on this blog for focusing too much attention on issues which are ever increasingly less relevant to the autism communities. I think Dr. Gorski’s comment is not a failure on his part, but, rather, on mine. While I have discussed both the Simons and Marks foundations, it is well worth the time to discuss them again. Any real change privately funded research may bring to the lives of autistics will come from groups such as these.

Autism and mental retardation – genetic overlap

30 May

Post taken from Medical News Today

Researchers working with Professor Gudrun Rappold, Director of the Department of Molecular Human Genetics at Heidelberg University Hospital, have discovered previously unknown mutations in autistic and mentally impaired patients in what is known as the SHANK2 gene, a gene that is partially responsible for linking nerve cells. However, a single gene mutation is not always enough to trigger the illness. In some cases, a certain threshold of mutation must be exceeded. The researchers conclude from their results that a correct inner structure of the nerve cell synapses is necessary to enable the normal development of language, social competence, and cognitive capacity. Essential for the success of the project were the studies by the Heidelberg research team with the doctoral student Simone Berkel and collaboration with a Canadian research team headed by Steve Scherer. The study has already been published online in the leading scientific journal Nature Genetics.

Autism is a congenital perception and information-processing disorder of the brain that is often associated with low intelligence, but also with above-average intelligence. The disease is characterized by limited social communication and stereotypical or ritualized behavior. Men are affected much more frequently than women. Autism and mental retardation can occur together but also independently of one another and are determined to a great extent by hereditary factors. Some of the responsible genes have already been identified but the precise genetic mechanisms have not yet been explained.

Genetic makeup of hundreds of patients analyzed

Professor Rappold and her team focused their studies on the SHANK2 gene, which encodes a structural protein at the nerve cell synapses. It is responsible for the mesh structure of the basic substance in the postsynapse. Only when the postsynapse is properly structured can nerve impulses be correctly transmitted. The researchers analyzed the genetic material of a total of 396 patients with autism and 184 patients with mental retardation. They found different mutations in their SHANK2 genes in the area of individual base pairs, but also variants in the number of gene copies. The mutations led to varying degrees of symptoms. None of the observed gene variants occurred in healthy control persons. “Apparently an intact postsynaptic structure is especially important for the development of cognitive functions, language, and social competence,” explained Professor Rappold.

Identical mutations as the cause of different diseases

Some of the genetic mutations identified were new occurrences of mutations that were not inherited from the parents, but some of the mutations were also found in one parent. Since there are also healthy carriers of gene variants, we must assume that a certain threshold of gene mutations must be exceeded for the disease to appear. “Moreover, the same mutation can be present in an autistic patient with normal intelligence and in a mentally impaired patient,” said Professor Rappold. There is some overlap in the clinical symptoms of mental retardation and autism, which can now be explained by a common genetic cause.

Polls show vaccine refusers are mainstream?

29 May

This is the claim put forth in a recent “vaccine choice” rally. You’ve probably already read about the rally in Kev’s piece The American Rally for Personal Rights – bit of a damp squib. In his piece on the rally, Is the anti-vaccine movement fizzling?, Orac has videos courtesy of Bruce Critelliplus.

The rally started out with (amongst other statement) a statement from the conference organizers pointing to a survey they commissioned:

“We are mainstream America! And there’s no denying it. We have some important and special news to announce that was shared earlier this week in a press conference. Three weeks ago the center for personal rights contracted with Harris Interactive to conduct a national survey, the first of its kind…..

And here are the results:

Today, the majority of American Parents believe that they should have the rights to decide which vaccines their children should receive without regard to mandates

http://vimeo.com/moogaloop.swf?clip_id=12082474&server=vimeo.com&show_title=1&show_byline=1&show_portrait=0&color=&fullscreen=1

Chicago AntiVax Rally May 26 2010-Part 1 from Bruce Critelli on Vimeo.

If you’ve read this blog much before, you probably know I like to look at the numbers. So I checked the poll.

Here’s the first question:

All children should receive 69 doses of 16 vaccines before age 18, as recommended by the federal government.

Wow. All children? The Federal government does not recommend that all children get vaccines, in any number. The federal government acknowledges that some children are unable to be vaccinated due to medical conditions.

So, I would have disagreed with question one. Strongly. Does that mean that I agree with the center for personal choice? Hardly.

How many people did agree with question 1? 42%. Another 39% were neutral. I put it that the majority of people polled (and whoever wrote that question) do not understand the vaccine program.

Kind of makes it hard to take the rest of the poll seriously.

But, I like to look at trends. One trend I keep being told is valid is that vaccine refusers tend to be more educated and more well off financially. Basically, smart successful people tend to question vaccines, with the implication that this means the idea has merit.

The poll doesn’t bear this out.

Take question 2, the Government Mandate question quoted in the rally:

“Parents should have the right to decide which vaccines their children receive without government mandates.”

Parents with a high school education or less were in favor 51% of the time

Parents with a college education were in favor 57% of the time

Parents with grad school education? 48% of the time. Still high, but isn’t that interesting. Grad school educated parents were about 10 points less favorable to the idea than college educated parents.

How about income levels?

Parents with $75K annual income were in favor 48% of the time. Still high, but isn’t that interesting. High income parents were about 10 points less favorable to the idea than middle class families.

The income trend–where the high income parents were much less favorable than the middle income families–was the case for 4 of 5 questions:

Parents should have the right to decide which vaccines their children receive without government mandates.

I am concerned about serious adverse effects of vaccines.

The government should fund an independent scientific study of fully vaccinated vs. unvaccinated individuals to assess long-term health outcomes.

I am concerned that the pharmaceutical industry has undue influence over government vaccine mandates.

Frankly, I’d probably be counted as supporting the ideas of the self-styled vaccine choice movement based on careful wording of surveys. Doesn’t mean I actually support those organizations.

As an aside, the effort to rebuild Dr. Wakefield’s image is on. It’s just really weak. Dan Olmsted blogged about it at the Age of Autism blog. It is a rather odd piece. First, Dan Olmsted, regular at the Autism One conference (this rally was basically a satellite to that conference), didn’t attend the rally. Nor did any of the principle AoA bloggers. Mr. Olmsted finishes his piece with a statement about how autism was invented in America with thimerosal….How that supposedly supports Mr. Wakefield and his MMR hypothesis, I am unable to ascertain.

Mr. Wakefield’s book came out this week. You can read a good review of it here, Andrew Wakefield Fights Back, and save yourself the time and money of buying the book. Mr. Wakefield’s supporters have targeted Amazon.com to boost the ratings of the book, pushing it to something under 20 in the new books bestsellers list. At the same time, Barns and Noble had the book at about 28,000. In other words, don’t expect it to be on any real best seller lists soon. They are just manipulating a rather useless number.

Age of Autism called for a rally to support Mr. Wakefield following his appearance on the Today Show. There is no followup, no pictures and the post calling for the rally is rather uncluttered by comments from people claiming to have attended. Not even a comment from David Kirby, a short subway ride away. I really wish I had been there with a camera to see if there was any turnout at all.

On short notice, skeptics were able to rally more people to attend the “vaccination choice” rally in Chicago.

Yes, a fair fraction of the roughly 200 people who attended the rally were there as a protest. The rally, timed to coincide with the AutismOne conference, pulled only a small fraction of the AutOne attendees.

Are these groups “mainstream”? Do they represent the real thoughts of the people? I rather think not.

There’s been a bit of a blogstorm this week on Andrew Wakefield. I’m sure he will pop up from time to time in the future, but, let’s face it: He’s old news. He’s been telling everyone who will listen that “he’s not going away”. Doesn’t mean he’s still relevant.

Social influence and the autism epidemic

28 May

Prof. Peter Bearman at the University of Columbia has spent considerable effort studying the autism data from the California Department of Developmental Services.

I wrote about Prof. Bearman’s paper Social influence and the autism epidemic before. It just popped up in pubmed.

When I checked the website for the center where Prof. Bearman’s team works, I found the press release from the paper:

Study: “Social influence” playing role in increased autism diagnoses

Social influence plays a substantial role in recent increases in autism diagnoses, according to a study in the March, 2010 issue of the American Journal of Sociology.

The study, by researchers from the Institute for Social and Economic Research at Columbia University, found that children living near a child who has been previously diagnosed with the disorder are far more likely to be diagnosed themselves in the following year. The proximity effect is not due to environmental factors or contagious agents, the study found. Rather, it is due mainly to parents learning about autism from other parents who have a child diagnosed with autism.

“We show that the likelihood of getting an autism diagnosis is clearly associated with person-to-person transmission of information,” said Peter Bearman, a sociologist who authored the study along with Ka-Yuet Liu and Marissa King. “Parents learn about autism and its symptoms; learn about doctors who are able to diagnose it; and learn how to navigate the process of obtaining a diagnosis and services from parents who have already been through the process with their own child.”

The researchers stress that the results do not mean that autism is not real or that it is overdiagnosed. “Our study doesn’t address the underlying cause of autism,” Dr. Bearman said. “We are describing the mechanism by which the number of diagnoses is increasing. It could be that the real incidence of the disorder is only now being uncovered. I think that is a reasonable message from this paper.”

In California, where this study was conducted, the number of autism cases handled by the California Department of Developmental Services increased 636 percent between 1987 and 2003.

The Columbia University team looked at data on over 300,000 children born between 1997 and 2003 throughout California. The team found that children who live within 250 meters of a child with autism have a 42 percent higher chance of being diagnosed with the disorder in the following year compared with children who do not live near a child with autism. Children who lived between 250 meters and 500 meters from a child with autism were 22 percent more likely to be diagnosed. The chance of being diagnosed decreases significantly the farther children live from another child with autism.

The study used several tests to determine whether these results could indeed be explained by a social influence effect, or if environmental toxicants or a virus are to blame. For example, the researchers looked at children who live close to each other, but on opposite sides of school district boundaries. These children are likely exposed to the same environmental conditions, but their parents likely belong to different social networks. The research shows that the proximity effect only exists when parents reside in the same school district. Children who live equally close to a child with autism but in another school district were no more likely to be diagnosed with the disorder than children who do not have a neighbor with autism.

The results also showed the proximity effect to be strongest among children on the milder side of the autism spectrum. That is also consistent with a social influence explanation, Dr. Bearman says. “Parents of severely disabled kids are more likely to recognize the disorder without needing input from social contacts, so we would expect to see a weaker social influence effect there, and that’s exactly what we found.”

The Strength of Social Influence

The data set used in the study allowed the researchers to judge just how strong the influence effect is compared to other factors that may be driving the epidemic. For example, previous studies have found a link between autism and parents’ ages. Parents today are having children later in life, and that could be causing autism cases to increase. Other studies have found that parents’ education plays a role as well. Better educated parents may be more likely to obtain a diagnosis for their children.

The Columbia team found that each of these factors plays a role in the epidemic, but the social influence phenomenon was the strongest. The researchers estimate that the proximity effect explains about 16 percent of the recent increases in autism diagnoses. Put another way, if no child lived within 500 meters of a child with autism, there would be a 16 percent reduction in autism diagnoses. That effect was stronger than the other factors tested. For example, the mother’s age explained about 11 percent of the increase. The mother’s education accounted for 9 percent.

The study was funded by the NIH Pioneer award for innovative health research.

What caught my eye was that last paragraph, where they note that 16% of the increase can be accounted for from this social influence phenomenon, but also that 11% was due to increased maternal age and maternal education accounts for another 9%.

This is in addition to diagnostic substitution, which accounts for about 25% of the increase in the CDDS client caseload.

One of the footnotes in the Social Influence paper also caught my eye:

The strong positive association of autism (during the period of increasing prevalence, 1992–2000) with socioeconomic status (King and Bearman 2009b), coupled with the increasingly negative socioeconomic status gradient for MR (arising from differential abortion rates for fetuses identified as chromosomally damaged through amniocentesis), has led to a relative stigma reversal and a consequent decline in the rate of MR diagnoses.

King and BEarman, 2009b is a “working paper” at Columbia University (“The Increased Prevalence of Autism.” Working paper. Columbia University, Paul F. Lazarsfeld Center for the Social Sciences.)

One feature that is very interesting in the paper is the how the level of “functioning” of the child relates to the social influence effect. The basic result of the paper is that when a family lives near another family with an autistic child, they are more likely to obtain CDDS services under the autism label. That effect is stronger for “high functioning” autism. To me, at least, this seemed counter intuitive. Here is a graph from the paper showing that the social influence effect means that a child with “high-functioning” autism is about 40% more likely to be registered with the CDDS if he/she lives close to a family with an autistic child.

The trend with proximity is very clear, as shown in the figure below. The probability of a child be registered with the CDDS with an autism label drops off very smoothly and clearly with distance to a family whose child was recently diagnosed. This is not seen for mental retardation.

As the authors point out:

Compared with children who are 501 meters–1 kilometer away from their nearest neighbor with autism, those in close proximity (1–250 meters) to a child with autism have a 42% higher chance of being diagnosed with autism in the subsequent year. Proximity of 201–500 meters increases the chance by 22%. In contrast, being farther away from a child with autism reduces the chance of a diagnosis.

I know this is a repeat in many respects. But I also have found this work to be very interesting and thought it worthwhile to bring up these points I didn’t discuss before.

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