Nov 27 2009
Answering Some Autism Questions
Like my science-blogging colleagues, I get e-mail. I always appreciate it when readers (or listeners, in the case of the SGU) take the time to write. Sometimes the e-mails are questions from someone who disagrees with my position on a hot issue. I especially like these e-mails – they are good blog fodder, and I think the format of answering questions is more compelling and interesting than making a didactic argument.
Below is an example of the kind of question I most like to get – from someone who disagrees with me, but still manages to ask polite and cogent questions. This stands in stark contract to most hostile e-mail I get, which are just strings of ad hominems, straw men, and other logical fallacies. I get the impression (and some of my e-mailers have later even admitted this) that the e-mails were not meant as an opening to serious discussion, but as a venting rant into the ether of the internet.
Harold asks some very important questions about the alleged autism-vaccine link and research priorities, and I am happy for the opportunity to clarify my position. His e-mail begins below the fold:
Dear Dr. Novella
I am a parent of a 13 year old boy with Autistic Disorder. I also have a blog site on which I commented unfavorably on your response to the possibility that the IACC might recommend some vaccine autism research. I ask your response to a few questions if you have the time and are inclined to respond.
One is your apparent opposition to any further research exploring possible vaccine autism connections. I am not an “anti-vaxxer”. I have never attributed my son’s autism to vaccines. Until recently I accepted the official view that vaccines play no role in causing autism. More recently my views have moved toward an undecided position. This change began when reading Dr. Bernadine Healy’s observations about the limitations of the epidemiological studies which are usually used to allegedly “debunk” any vaccine autism connection. In her comments she indicated that such studies are not specific enough to address the possible impact of vaccines or their ingredients on potentially vulnerable population subsets.To this layperson Dr. Healy’s criticism seems reasonable as does her call, a call also made by Dr. Julie Gerberding, that an observational study comparing autism rates in existing vaccinated and non vaccinated populations could and should be done. Your opposition to further vaccine autism study does not, with respect, seem either reasonable OR science based. I ask if you could provide a clear rationale for opposing a study which has been called for by two prominent health authorities and which might provide useful information to what is a heated debate on all sides.
The second question I have for you concerns the increases in autism diagnoses which has really been quite startling by any measure. In my son’s lifetime the figure has changed from 1 in 500 to 1 in 150 with the two recent studies indicating it might now be 1 in 91. Many authorities dispute though that the increases are real pointing to the autism definition changes in the DSM and ICD diagnostic manuals in the 1993-4 period and increased social awareness as the reasons for the increases in diagnoses. Is it your view that the increase in autism diagnoses does not reflect a real increase in autism disorders? If so what are the implications of that position for the argument that epidemiological studies have disproved any thimerosal vaccine link because autism rates increased after removal of thimerosal from MOST vaccines?
Also if you have the time and inclination do you think Dr. Healy’s observations that thimerosal which continued to be found in flu vaccines, some of which historically were administered to pregnant mothers, was a matter worthy of investigation given that the thimerosal crosses the placenta is a legitimate concern worthy of further investigation? This is an important matter here in Canada where the squalene adjuvant was removed from the vaccines given to pregnant women but there has been no indication that thimerosal has been removed.
I would genuinely appreciate your responses to these questions which I am posting on my blog site. If you do me the courtesy of an informed reply I would be happy to post that reply as well.
Respectfully,
Harold L Doherty
And here is my response:
Harold,
Thanks for your thoughtful e-mail. I would be happy to address your questions.
Regarding further research – it is always possible, in the face of negative results, to call for still more research. And it is easy to make this seem like the default scientific position. ESP proponents, after a century of failed research, call for still more research, and accuse anyone who says further research is not worthwhile of being unscientific.
Also, to clarify my position, I am not categorically against further research into vaccines and autism. I think any such research is most likely to confirm the lack of a correlation. And if there is a susceptible sub-population, of course it would be good to know about it to make the vaccine program even safer. (But keep in mind – it is a common form of special pleading to argue that, when the effect you are looking for is absent, that it only exists is a subpopulation that existing data was not powerful enough to detect. This may be true, but it is just post-hoc speculation, and doesn’t change the fact that the data is negative.)
My position is that ideological groups should not be dictating how scarce research funds are allocated. When we put money, people, and resources into chasing down an unlikely hypothesis those resources are not available for what might be more promising research. My position is that objective scientists, justifying their position with a careful analysis of the research, should decide how best to allocate scarce research funds. The anti-vax movement, however, is trying desperately to put their thumb on the scale – and that is what I oppose. They are trying to subvert autism activism to serve an anti-vaccine agenda – and they are hurting the autism community as a result, in my opinion.
I respect Healy and Gerberding, but I disagree with their approach in that they think more research will satisfy vaccine critics, but this is a naive position. The anti-vaccine movement has already demonstrated that they are impervious to facts and evidence, and spending time and money trying to placate them is a fool’s errand. The CDC even went as far as to include them in designing a trial looking at vaccines and neurological disorders, and then only after the results came back negative, did they criticize the study.
You specifically mention an observational study comparing vaccinated and unvaccinated children – I do not oppose this. If it can be done with reasonable resources, there are scientists willing to carry out such a study and think it is worthwhile, and the results will be useful, then I fully support it and await the results. (And in fact I have never opposed such studies.) What I and others have written is that an experimental (not observation) comparison of vaccinated vs unvaccinated children is unethical, because it would randomize children to not get standard preventive care, and that directly violates human research ethical guidelines. Observational studies are fine, but they are never definitive, and they will not, in my opinion, change or end the debate. They will not move the anti-vaccinationists one bit.
The increase in autism diagnoses has been studied from multiple angles – not just the expansion of the diagnosis.
You will find a summary of relevant research here: http://sciencebasedmedicine.org/reference/vaccines-and-autism/
So far, every way it has been looked at the hypothesis that the increase in diagnosis of ASD is due to increased surveillance and expanded diagnosis has been confirmed. There is evidence of diagnostic substitution (as ASD numbers increase, the numbers of other similar diagnoses decrease). There is evidence that different age groups have the same prevalence of ASD (rather than increasing with younger age, as would result from a true increase in ASD). And if you apply the same diagnostic and surveillance methods to a cohort over time, you get the same ASD prevalence. The data is actually quite convincing that true autism rates are not significantly increasing (you cannot rule out a small real increase, or decrease for that matter, that the data is not powerful enough to detect) but that there has been expanded diagnosis with diagnostic substitution and increased surveillance.
I discuss this further here (http://www.sciencebasedmedicine.org/?p=95) and here (http://www.sciencebasedmedicine.org/?p=340)
The implications of this position to the alleged thimerosal link are complex, but support a lack of correlation. What the data shows is that in various countries ASD diagnoses began to rise around the same time (as diagnostic patterns changed), in the early 1990s, and have continued to rise through today. Meanwhile, vaccine policies have varied considerably with regard to total thimerosal dose, with several countries, at different times, removing most thimerosal from vaccines. Every study looking at the data shows no correlation between the steadily increasing ASD diagnostic rates with the rising and falling thimerosal doses at different times in different countries. This is powerful evidence for a lack of correlation. As you likely know, toxicity is always about dose, and seeing a proper dose-response is essential to proving toxicity causation. What we have with thimerosal is an absolute lack of any dose-response, in many studies and sets of data.
Also, please keep in mind that the anti-vaccine movement used the increase in ASD in the 1990s as their original justification for the claim that thimerosal causes autism. They predicted that autism rates would decline after thimerosal was removed from the childhood vaccine schedule, and we agreed that if that happened we would need to rethink the possibility of a connection. Well, rates continued to rise without a blip, effectively putting the final nail in the coffin of the thimerosal hypothesis.
Regarding thimerosal and pregnancy, to the extent that this has already been studied (again, you can find references in the vaccine-and-autism link above) there has been no correlation. I do not oppose further research, however, if the CDC or others think it is warranted and feasible.
Thanks again for the interesting questions, and I hope this adequately clarifies my position.
Regards,
Steve Novella
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18 Responses to “Answering Some Autism Questions”
Wow, I wish everyone who is wary of vaccines were able to ask questions and think things through like Harold is.
It seems like most people who would fall into the anti-vax category aren’t even able to come up with a clear reason why they’re questioning vaccines, they just don’t like the idea of doctors injecting something into them or their children.
Harold has clearly thought this through, and it makes me happy that he hasn’t decided one way or another, he’s genuinely asking questions, and he’s actually hoping for answers unlike anti-vaxxers who just plug their ears when you try to respond to them.
Is it just me, or has everyone with an autistic child been told about the vaccine-autism nonsense? It’s kind of disheartening to think that the anti-vax movement is so effective in spreading their lies, especially since not everyone will think as hard about what they’re reading as Harold. It’s really sad to think that some parents may blame themselves for their child’s autism since they took them to get the vaccine.
Great job once again Steve in responding to Harold’s questions! I wish that the voices of reason like yours were more visible.
Excellent questions – exactly the kind of questions an intelligent layperson SHOULD be asking.
Equally excellent answers. You have a way of clarifying complex issues without dumbing them down.
Steve,
Great post. Just a nit pik…. you keep saying “data is” in your text. Shouldn’t it be “data are”? Maybe I’m wrong but it seems like I read this some time ago in some journal.
For what it’s worth.
Chet
ESP proponents ask for more research because of the successful studies, not the failures.
Sometimes scientists think of data as plural, as in These data do not support the conclusions. But more often scientists and researchers think of data as a singular mass entity like information, and most people now follow this in general usage.
Oops, I only got part of my message that time. Here is the complete comment.
@Eyewrite. You are correct about data, although of course it is a nitpick. I try to be relatively tolerant of minor grammatical and spelling errors in blog posts and comments, except for the few cases where they make it extremely difficult to decide what the person really means, because I recognize that the people who write those posts are devoting a lot of their time at very little or no compensation in order to give me something interesting to read. Thus, they don’t have much time to do a careful edit of their work and I use the same rules in judging them that I would use for casual speech.
Still, having studied a couple years of high school Latin, as well as a little French and Russian, I do get irritated at times by the misuse of foreign language plurals, especially Latin plurals.
FWIW, the word data is the plural of datum, although one online dictionary that I checked gives datums as an alternate plural. The Microsoft Word spelling checker doesn’t even like that one!
I think this quote from the Free Online Dictionary summarizes the situation pretty well:
“Sometimes scientists think of data as plural, as in These data do not support the conclusions. But more often scientists and researchers think of data as a singular mass entity like information, and most people now follow this in general usage.”
I also get irritated by the near ubiquitous use of media as a singular. Television is one medium for communicating, radio is a different medium, magazines are a medium, books are a medium, the internet and especially the worldwide web is a medium, et cetera, et cetera. When people talk about the “television media (sic)”, do they really think that the CBS television network is a different medium from the NBC network? Somehow, I doubt it.
This brings me over to the recent hubbub about using facilitated communication to allow a possibly locked-in accident victim to communicate with the outside world. In this case, the facilitator is the “medium” and without independent and carefully tested confirmation of the communication, this medium has no more validity than using a medium to talk to your dead cow. In this case, I think Marshall McLuhan really hit the nail on the head when he said, “the medium is the message.”
Enough already.
I think Cranberry juice is a good example of research following a hypothesis, even when lots of negative data is available.
We know with about as much certainty as any medical intervention that (orally administered) Cranberry juice does not cure urinary tract infections. The reason we know this is this is what the herbal folk believed (and many still believe), so there are now ample negative clinical trials in the literature.
In these trials it was noted several times that Cranberry juice may be effective against infections where the Cranberry juice comes into contact with the infected area (think stomach). But it was a while before anyone did that clinical trial (Helicobacter. 2005 Apr;10(2):139-45). Turns out that Cranberry juice is effective against H Pylori, I’m not sure one should take it as opposes to antibiotics, but one of those cases where a “complementary” approach is unlikely to be controversial.
I think a case can be made that the potential medical benefits of Cranberry juice were misunderstood due to prior hypothesis, and ignoring -ve results.
It is a good example because it is uncontroversial topic (outside of those who believed it worked for UTI). And the alternative hypothesis that should have been investigated was even pointed at in the previous trials. Oh and the nice outcome that Cranberry juice probably is good for you, just not the way that was believed before.
But the capacity to underestimate the significants of contradictory evidence has been highlighted as a key flaw in thinking in some woo believers.
The use of ESP as an example in this discussion is distracting and counterproductive.
This is unfortunate because it undermines what I think is an important message—vaccines are safe and effective.
The actual state of evidence regarding ESP (remote viewing specifically) includes the following:
From Brian Josephson, a world renowned Nobel Prize-winning physicist from Cambridge University.
“The experiments have been designed to rule out luck and chance. I consider the evidence for remote viewing to be pretty clear-cut.”
From Prof. Wiseman- recipient of the CSICOP Public Education In Science Award 2000
“I agree that by the standards of any other area of science that remote viewing is proven, but begs the question: do we need higher standards of evidence when we study the paranormal? I think we do….
(He continues making an argument from personal incredulity as to why he feels more evidence is needed–)
Read more: http://www.dailymail.co.uk/news/article-510762/Could-proof-theory-ALL-psychic.html#ixzz0YJnZtOTP
By using ESP as an example are you suggesting that Nobel-prize winning physicists and leading skeptics agree that the evidence that autism is caused by vacines is proven by the standards of science? Or that the evidence is pretty clear-cut?
I don’t think that is what you mean to imply.
I’m guessing that you are somewhat illinformed as to the actual scientific evidence in this case (ESP) – but starting your reply in this manner doesn’t bolster confidence in how well you are informed about vacines and autism— which is a shame because I think you are well informed in this area and have important things to say.
Remote viewing? HAHAHAHAHHAHAHA
Professor Wiseman doesn’t believe for a second in such nonsense. He tried to be too clever with his quote (which went WAY over the head of the daily mail reporter).
RV has NOT been proven in relation to ANY area of science.
eiskrystal-
pooh-pooh followed by the unsubstantiated claim that Prof. Wiseman didn’t mean what he said and closed with an unreferenced claim that is in disagreement with any number of well respected researchers (including Jessica Utts and the aforementioned Prof Wiseman).
I took out my pencil and pad, thought long and hard of “Jessica Utts” until it seemed I had found and entered the remoteness of a soul-like spiritual presence, and somewhere from the back of beyond I saw and drew a crocoduck.
sonic, I can’t tell if you are serious or just trying to get your jollies by erking skeptics.
If you are serious, there is a 1 million dollar prize waiting for you and whoever you can find with the ability to utilize extra-sensory perception.
http://www.randi.org/site/index.php/1m-challenge.html
Care to explain how this prize has gone unclaimed since 1964?
If you aren’t serious, please waste your time trolling an anti-vax or creationist forum. They are more fun to hassle.
Also, I just went to Professor Wiseman’s personal website. Nowhere does he endorse or support the view that a person has ever been shown to have a “paranormal” ability.
http://www.richardwiseman.com/research/parapsychology.html
“The CDC even went as far as to include them in designing a trial looking at vaccines and neurological disorders, and then only after the results came back negative, did they criticize the study.”
I’d like to read more about this. Can anyone point me in the direction of this study and who was involved? Thanks.
OedipaMaas checkout this discussion on that study and the sour grapes it caused in the anti-vax contingent:
http://scienceblogs.com/insolence/2007/09/a_bad_day_for_antivaccinationists.php … the end of the posting are links to other comments.
For more on how these people behave, check out the Skepchick blog (I don’t know how many URLs I can use here) for Rebecca’s posting with the title The Misogyny of the Anti-vaccination Cult. This should make next week’s SGU podcast very interesting!
Speaking of podcasts, the Are We Alone podcast from SETI has finally arrived at their website. It a Skeptic Check on vaccines, and includes Steve Novella… and the doctor the anti-vaxers hate the most, Paul Offit! (it is at radio.seti dot org)
Sonic, Jessica Utts took the research that had been done and applied statistical analysis to it. That is all. That says nothing about the quality of the research. I’m sure with some loose protocols statistical analysis WOULD show an effect. Her opinion then becomes rather meaningless.
It is also not an unsubstantiated claim that Wiseman does not believe in RV. Its in the original article. You yourself had to say “personal incredulity as to why he feels more evidence is needed”
So he doesn’t believe it and wants to see better research by your own words. Hardly a glowing recommendation.
I did not claim Prof. Wiseman thought the experiments proved RV, but that,
“I (Wiseman) agree that by the standards of any other area of science that remote viewing is proven,…”
Dr. N is making fun of people who say “more research is needed,” by using the ESP example. Does he really mean to make fun of Prof. Wiseman? Why bring it up at the start of an article about vaccines? What does it add to what follows?
I have not stated that ESP is real, only that the evidence for is very strong (see Wiseman) and that it is seen as convincing by at least one Nobel Prize winning physicist (Josephson). What I get as a response from the readers (eiskrystal and CivilUnrest and artfulD) is pooh-pooh and nonsequitur (illogic). (Responses that are so poorly researched that they don’t even realize they are making fun of the work of Ray Hyman—the other half of the Jessica Utts team)
This does not lead to confidence that there is any real evaluation of the data re: vaccines (even though I think there is).
I think the anaology between anti-vaxxers and ESP researchers is inappropriate, distracting and counter-productive.
I say no more–
sonic:
Making fun of Ray Hyman? Here’s part of what he said about Utts’ conclusions:
(From: http://www.mceagle.com/remote-viewing/refs/science/air/hyman.html )
“However, the occurrence of statistical effects does not warrant the conclusion that psychic functioning has been demonstrated. Significant departures from the null hypothesis can occur for several reasons. Without a positive theory of anomalous cognition, we cannot say that these effects are due to a single cause, let alone claim they reflect anomalous cognition. We do not yet know how replicable these results will be, especially in terms of showing consistent relations to other variables. The investigators report findings that they believe show that the degree of anomalous cognition varies with target entropy and the `bandwidth’ of the target set. These findings are preliminary and only suggestive at this time. Parapsychologists, in the past, have reported finding other correlates of psychic functioning such as extroversion, sheep/goats, altered states only to find that later studies could not replicate them.”
The joke here was not even remotely on Ray Hyman. If you have viewed it differently, perhaps you are more sheep than goat.