Science-Based Medicine

April is National Autism Awareness Month, and as of today April is nearly half over. Do you notice anything different compared to the last couple of years? I do. Can you guess what it is?

The anti-vaccine movement’s usual suspects haven’t been all over the mainstream media, as they usually are this time every year, often as early as April 1 or even March 31. In fact, over the last couple of years I had come to dread April 1, not because it’s April Fools’ Day (although the things that made me dread that particular day were often indistinguishable from an April Fools’ Day prank, so full of idiocy were they), but rather the expected carpet bombing of the media by the likes of Jenny McCarthy, J. B. Handley, and their ilk, some or all of whom would show up on various talk shows to spread their propaganda that vaccines cause autism. For instance, last year Jenny McCarthy and her former boyfriend Jim Carrey showed up on Larry King Live! with Dr. Jerry Kartzinel (her co-author on her latest book of autism quackery) and J. B. Handley, the last of whom even contributed a guest post on Larry King’s blog, in which he touted an incredibly bad, pseudoscientific “study” commissioned by Generation Rescue. The “study” (and calling it a “study” is way too generous) was no more than cherry-picked random bits of data twisted together into a pretzel of nonsense, as I described. Around the same time, Jenny McCarthy was interviewed by TIME Magazine, an interview in which she uttered these infamous words:

I do believe sadly it’s going to take some diseases coming back to realize that we need to change and develop vaccines that are safe. If the vaccine companies are not listening to us, it’s their fucking fault that the diseases are coming back. They’re making a product that’s shit. If you give us a safe vaccine, we’ll use it. It shouldn’t be polio versus autism.

Soon after, Generation Rescue created a website called Fourteen Studies, which they promoted hither, thither, and yon. The idea of the website was to attack the main studies that failed to find a link between vaccines and autism and to promote the pseudoscientific studies that anti-vaccinationists like. In 2008, it was pretty much the same — well, worse, even. When she appeared on Larry King Live! with our old “friend,” anti-vaccine pediatrician to the stars, Dr. Jay Gordon, McCarthy shouted down real experts by yelling, “Bullshit!” (behavior trumpeted by Rachel Sklar of the Huffington Post).

This year? Oddly enough (and to me unexpectedly), there’s been almost nothing. J.B. Handley seems to be the man who wasn’t there. Well, not quite. It turns out that J. B. Handley has managed to get a little bit of fawning media attention, but just a little bit, in the form of an interview in The Bloomington Alternative entitled J. B. Handley: It’s unequivocal; vaccines hurt some kids. Apparently Mr. Handley has come down quite a bit in the world. Where’s his appearance with Jenny on Larry King Live! this year? Maybe it’s coming in the second half of the month. Or maybe the mainstream media, in the wake of the fall of Andrew Wakefield, have finally figured out how disreputable Generation Rescue is when it comes to vaccines. In the meantime Steven Higgs will have to do as a new mouthpiece for the anti-vaccine movement.

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Just when I thought I was out… they pull me back in.

Michael Corleone in The Godfather, Part 3

I hadn’t planned on doing two vaccine posts with such a short interval between them, but all too often, as the they say in the weakest of the Godfather movies, I get pulled back in again. So, after noting last week that 2009 was shaping up–fortunately–to be a very bad year for antivaccinationists, I should have expected a counterattack from the antivaccine fringe. Indeed, the only thing that surprised me after the twin blows of the revelations about scientific fraud on the part of the originator of the claim that the MMR vaccine causes autism, Andrew Wakefield, and the resounding defeat of the first three test cases of the Autism Omnibus proceedings, was that it took longer than I had expected. True, a group had formed, proclaiming that “we support Dr. Andrew Wakefield.” Also true, the antivaccine activists at the Age of Autism have been working overtime to attack the Autism Omnibus as being hopelessly rigged. Indeed, our “old friend” Dr. Jay Gordon has even likened attempts to refute antivaccine pseudoscience to tobacco companies’ P.R. and astroturf campaigns back in the 1950s through 1980s to cast doubt on the strong scientific and epidemiological evidence showing that cigarettes cause lung cancer.

But those contortions of science, epidemiology, law, and logic were merely a warmup for the real counterattack. On February 25, Generation Rescue purchased this full page ad in USA Today:

Unfortunately, the advertisement above was only the beginning. Generation Rescue managed to team up the chief progagandist for the antivaccine movement, David Kirby, along with Robert F. Kennedy, Jr., whom I have discussed before for his total support of the antivaccine movement. The question then becomes: Where would these two team up to spread their message against vaccines? Do you even have to ask?

Their twin articles appear on that repository of all things antivaccine, The Huffington Post, under the title Vaccine Court: Autism Debate Continues. As I will explain, these twin articles represent yet another example of what I have at times referred to as the “incredibly shrinking vaccine-autism hypothesis.”
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The anti-vaccine movement is nothing if not plastic. It “evolves” very rapidly in response to selective pressures applied to it in the form of science refuting its key beliefs. For instance, when multiple studies looking at the MMR vaccine and autism failed to confirm the myth that the MMR causes autism or “autistic enterocolitis,” most recently late last year, it was not a problem to the anti-vaccine movement. Neither was it a major problem to the movement when multiple studies similarly failed to find a link between mercury in the preservative thimerosal that used to be in most childhood vaccines and is no more (except the flu vaccine) and autism. No problem! Andrew Wakefield is alleged, based on strong evidence, to have falsified his data alleging a link between the MMR vaccine and “autistic enterocolitis”? Fuggedabouddit! The anti-vaccine movement simply pivoted neatly, de-emphasized points that the evidence was so clearly against that even they couldn’t spin it to a positive anymore, and found new bogeymen. These days, it’s the “toxins” (such as formaldehyde and the latest antivax bogeyman, squalene), and “too many too soon” (a gambit given seeming respectability by Dr. Bob Sears and Dr. Jay Gordon, apologists for and supplicants to the anti-vaccine movement both.

However, there is one trait of the anti-vaccine movement that, however its camouflaging plumage may evolve, never, ever changes. It is as immutable as believers say that God is. That trait is that, whatever other claims, the anti-vaccine movement makes, at its core it is always about the vaccines. Always. No matter how often science fails to find a link between vaccines and autism or vaccines and whatever other horreur du jour the anti-vaccine movement tries to pin on vaccines, no matter how many studies do not support the viewpoint that vaccines cause autism, no matter how much the anti-vaccine movement tries to deny and obfuscate by saying that it is not “anti-vaccine” but rather “pro-safe vaccine,” at its core the anti-vaccine movement is about fear and loathing of vaccines. Always. When inconvenient science doesn’t support their views, anti-vaccine activists either ignore the science, distort the science, or launch ad hominems against the people doing the science or citing the science. And, as I said before, the claims of the anti-vaccine movement evolve. Never again will the anti-vaccine movement make the horrific mistake of yoking itself to a hypothesis that is as easily testable as the hypothesis that mercury in vaccines causes autism. The claim that mercury in vaccines causes autism predicted that, if thimerosal were removed from vaccines or reduced to pre-”epidemic levels” of the early 1990s, then autism rates should plummet. Thimerosal was removed from nearly all childhood vaccines (the sole exception being some flu vaccines), reducing infant mercury exposure from vaccines to levels not seen since the 1980s; yet autism rates continue to rise. This is about as resounding a refutation of the hypothesis that mercury in vaccines is a major cause or contributor to autism that even the anti-vaccine movement has backed away from the pure claim, which has now evolved to unnamed “environmental toxins,” either in concert with mercury or with other nasty things, as being the Real One True Cause of Autism.

It’s evolution in action. These new claims are much “fitter” because they are much harder to falsify through scientific research, epidemiology, and clinical trials.
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Regular readers of this blog may have noticed that I seem to have taken on the role of the primary vaccine blogger of this little group of bloggers trying desperately to hold the forces of pseudoscience and magical thinking at bay in the face of powerful forces trying to “integrate” prescientific belief systems with science- and evidence-based medicine, a process that would be unthinkable in just about any other field of applied science, such as aeronautics or the physics used in engineering, just as creationists try to “integrate” religion with biology. Although I do have a strong interest in the antivaccination movement in general and the claim that vaccines, or the mercury in the thimerosal preservatives that was in many childhood vaccines in the U.S. until late 2001 or early 2002 (when they were taken out) are a major cause or contributor to autism, such had not been my intention. When I started here on SBM, I had intended to be a lot more diverse. Indeed, I had even had another topic entirely in mind for this week’s post, but, as happens far too often, news events have overtaken me in the form of a story that was widely reported at the end of last week. It was all over the media on Thursday evening and Friday, showing up on CNN, Larry King Live, the New York Times, and NPR. It happens to be the story of a girl from Georgia named Hannah Poling whose case before the Vaccine Injury Compensation Program (VICP), which had originally part of a much larger proceeding known as the Autism Omnibus in which nearly 5,000 parents are petitioning the VICP for compensation based on the claim that their children’s autism were caused by vaccines, was settled by the government. This settlement was based on the observation that Poling had a rare genetic mitochondrial disease that may have been exacerbated by a series of vaccines that she had, after which, among many other problems, Hannah regressed and developed some autism-like symptoms and then months later a seizure disorder. Instantly, it was being trumpeted all over the Internet, blogosphere, and media that the government had “admitted” that vaccines cause autism. One particularly excitable antivaccinationist named Kent Heckenlively (whom we’ve met before), even went so far as to foreshadow the propaganda blitz that was to come as he wrote on the antivaccine blog Age of Autism a full week before this news blitz began:

It’s official.  The sky has fallen.  The fat lady has sung.  Pigs are flying.

[...]

In a settlement, the settling party tries to admit as little as possible.  It’s like what I imagine the settlement claim against Bill Clinton in the Paula Jones case must look like.  Nowhere in the document does he admit to dropping his pants in a hotel room and asking her to kiss it.  It likely says something along the lines of he concedes they were in a hotel room together, they were alone, and something happened which formed the basis of her law suit.

But we all know what happened there.  And we know what this settlement means.

The government just dropped its pants.

One thing this shows us is just how the blogosphere can be bubbling with information that lets one predict a public relations blitz like this. The mainstream press seemed to have been totally blindsided by this story, but if reporters had only been checking the right blogs, they would have known about it a full week before, if not longer. In any case, since Thursday, there has been a very well orchestrated public relations campaign to frame this settlement as the government “admitting” that vaccines cause autism. It’s not, as I will try to explain, but framing it that ways has thus far been a very effective PR strategy for antivaccinationists. In my nearly three years of following this topic, I thought that I had never seen anything like it before.

But I had.

This case is nothing more than a demonstration that everything old is new again and that, no matter what the science says, it’s always all about the vaccines, the claims of antivaccinationists otherwise notwithstanding, as I will now show. What we are seeing now, as we did a few years ago, is the rebranding of autism as a condition in order to serve the purposes of the antivaccination movement.
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A commonly misunderstood aspect of autism and autism spectrum disorders (particularly by antivaccinationists and believers in the quackery known as “autism biomed”) is that autism is not a condition of developmental stasis. It is a condition of developmental delay. Autistic children can and do exhibit improvement in their symptoms simply through growth and development. However, parents who subject their children to “autism biomed” quackery of the sort championed by Jenny McCarthy and others seem to view autism as a condition of developmental stasis. That’s why they so easily and predictably attribute any improvement in their children to whatever quackery du jour they are using on them. It’s also why, in order to determine whether a given intervention in autism has any real effect, randomized controlled trials are required. Indeed, it’s not so difficult to see why, if you take into account the widespread belief that autistic children do not improve, along with parents’ imperfect human memories riddled with confirmation bias, confusing correlation with causation, and other confounders like regression to the mean, so many parents believe that “autism biomed” treatments have actually helped their children. Moreover, improvements observed in autistic children tend to be uneven, with periods of little change interspersed with periods of rapid development. Should such a period of rapid development appear after a “biomed” intervention, guess what gets the credit for the improvement?

But how much improvement is possible? Do autistic children “recover,” and, if they do, how much can they recover? The autism biomed movement is rife with stories of “recovered” children, but often, if you investigate these stories, they turn out to be less than convincing, not unlike the way that alternative medicine cancer “cure” testimonials tend not to be so impressive when examined closely. However, in the case of autism, this isn’t always the case. There are clearly children who lose their diagnosis of autism or ASD, with observations published as far back as 1970, when Rutter reported that 1.5% of adults who had been diagnosed with autism were functioning normally, while 30 years later Sigman et al reported that 17% of autistic children in their group lost their diagnosis and 10 years after that Kleinman et al reported that up to 19% of autistic children “lose their diagnosis.” The reason for this observation is hotly debated, and until fairly recently it was often assumed that these children’s recoveries were in fact not true recoveries but children who were either misdiagnosed or overdiagnosed. Such an assumption made intuitive sense because such an outcome is more likely with children diagnosed with Asperger’s disorder or pervasive developmental disorder, not otherwise specified (PDD-NOS), both of which are categories that resulted from the expansion of the diagnostic criteria for autism. Be that as it may, when you boil it all down, it is estimated that between 3% and 25% of autistic children “lose their diagnosis.” However, few of these studies explicitly address whether the social and communication abilities of these children are fully typical.

A recent study might help clarify what degree of recovery is and is not possible. Most of the previous studies before this have been small and did not look specifically at the outcomes people are curious about. Published in The Journal of Child Psychology and Psychiatry by Fein et al and entitled Optimal outcome in individuals with a history of autism, this study got some news coverage last week under titles such as Some With Autism Diagnosis Can Overcome Symptoms, Study Finds; Scientists seek clues in kids who outgrow autism symptoms; Some children outgrow autism: study; Health Buzz: Can Autism Fade Over Time?; and Children ‘may grow out of autism’. The authors set the stage in their introduction after surveying the literature, some of which I’ve touched on above:
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I will begin this post with a bit of an explanation. Between one and two weeks ago, there appeared two momentous news about the manufactroversy regarding vaccines and autism. No doubt, many SBM readers were expecting that I, as the resident maven of this particular bit of pseudoscience, would have been here last week to give you, our readers, the skinny on all of this. Unfortunately, as some know, my wife’s mother died, coincidentally enough, on the 200th anniversary of Darwin’s birthday and a day when one of those two momentous bits of news was released to the public, which is why I used one of my handful of posts written and then held in reserve. I’m back now, though, and I don’t think it’s too late to comment on these bits of news because now that over a week has gone by what I’ve seen has led me to draw some conclusions that I might not have been able to do, had I done my usual bit and been first off the mark (at least among SBM bloggers) discussing the story.

2008: The Best of Years for the Antivaccine Movement

But first, let’s take a look at last year. In 2008, Jenny McCarthy was the new and fresh celebrity face of the movement that believes that autism and all manner of other neurodevelopmental disorders are caused by vaccines and that the government and big pharma are suppressing The Truth. She had emerged in the fall of 2007 after having tried to erase from the Internet her previous involvement in the “Indigo Child” movement in preparation for becoming an “autism advocate” who could write a book that could land her on Oprah’s show. Thanks to her and, perhaps even more so to the star power of her boyfriend Jim Carrey, who is just as wrong about vaccines and medicine as Jenny is, the antivaccine movement came roaring into prominence in a way that it had never managed to pull off before. After all, let’s face it, a former Playboy Playmate of the Year and a famous comedian are far more “interesting” public figures for various media outlets to interview than previous celebrities who spearheaded the vaccine manufactroversy, such as Robert F. Kennedy, Jr. or Don Imus and his wife Deirdre.

Indeed, Jenny’s combination of good looks and utter obnoxiousness led to her showing up all over the media in 2008. For example, on April 1 (appropriately enough), she appeared on Larry King Live! and shouted down physicians who had the temerity to tell her that her Google University knowledge was just plain wrong. The pinnacle of her influence came during the summer, when, having now supplanted J.B. Handley as the public face of the antivaccine group Generation Rescue and transforming GR into “Jenny McCarthy’s autism charity,” she led the “Green Our Vaccines” rally in Washington, DC. True, at most there were several hundred people there, but it got wide news attention, and Jenny was all over the news. She rapidly followed it up by releasing a second book Mother Warriors: A Nation of Parents Healing Autism Against All Odds and appearing on The Oprah Winfrey Show yet again.
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Arguably, the genesis of the most recent iteration of the anti-vaccine movement dates back to 1998, when a remarkably incompetent researcher named Andrew Wakefield published a trial lawyer-funded “study” in the Lancet that purported to find a link between “autistic enterocolitis” and measles vaccination with the measles-mumps-rubella (MMR) trivalent vaccine. In the wake of that publication was born a scare over the MMR that persists to this day, 11 years later. Although peer reviewers forced the actual contents of the paper to be more circumspect, in the press Wakefield promoted the idea that the MMR vaccine either predisposes, causes, or triggers autistic regressions. Even though over the next several years, investigations by investigative journalist Brian Deer revealed that not only was Wakefield’s research funded by trial lawyers looking to sue vaccine manufacturers for “vaccine injury” when he did his research (for which he is now being charged by the U.K.’s General Medical Council with scientific misconduct), but during the Autism Omnibus trial testimony by a world-renowed expert in PCR technology showed that he was incompetent. Even worse for Wakefield, in February 2009 Brian Deer published a news expose based on strong evidence that Wakefield may very well have falsified data for his Lancet paper.

None of this mattered. Andrew Wakefield still enjoys a cult of personality among the anti-vaccine crowd that no revelation seems able to dislodge, even the revelation that at the time he was both in the pay of trial lawyers and working on his study, Andrew Wakefield was also applying for a patent for a rival measles vaccine. Indeed, the anti-vaccine propaganda blog Age of Autism bestowed upon him last year its “Galileo Award” as the “persecuted” scientist supposedly fighting for truth, justice, and anti-vaccinationism against the pharma-funded or brainwashed minions of the “Church of the Immaculate Vaccination.” In the meantime, MMR uptake rates in the U.K. have plummeted over the last decade, far below the level needed for herd immunity, to the point where, last year the Health Protection Agency declared measles to be once again endemic in the U.K., 14 years after the local transmission of measles had been halted.

Since Wakefield’s study was released, a number of studies have shown that there is no epidemiologically detectable link between vaccination with MMR and autism, including one by a researcher who once appeared to be a believer in the idea that vaccines are somehow linked with autism, Mady Hornig. Hornig actually tried very hard to replicate Wakefield’s 1998 Lancet study, only this time with more children, and she found no link between MMR and autism using methodology similar to Wakefield’s. None of these studies has had any effect on the anti-vaccine movement, except to motivate them to circle the wagons even more, as J.B. Handley of Generation Rescue did when he launched a website called Fourteen Studies, whose purposes are to launch fallacious and pseudoscientific attacks on studies failing to find a link between vaccines and autism (often involving accusations of being a “pharma shill”), to promote the lousy science that gives the appearance of supporting the hypothesis that there is a link between the MMR vaccine and autism, and then slime anyone who points out how deceptive their attacks were.

Now, yet another study has been released studying whether there is a link between MMR vaccination and autism. Yet another study has failed to find a link between MMR vaccination and autism. Yet another study is all set to be attacked by Generation Rescue and the anti-vaccine movement. The sad and sordid history of reactions of the anti-vaccine movement to studies that do not support its belief in the unsinkable rubber duck of a myth that vaccines cause autism. This study was published online in The Pediatric Infectious Disease Journal by a group from Department of Epidemiology and Preventive Medicine, Jagiellonian University, Collegium Medicum, Krakow, Poland (a Polish group, my people!) and entitled Lack of Association Between Measles-Mumps-Rubella Vaccination and Autism in Children: A Case-Control Study. It’s yet another nail in the coffin of the myth that the MMR causes or contributes to autism. Indeed, this study not only shows that MMR vaccination is not associated with autism but that it may even be protective against autism. True, for reasons I will discuss shortly, I doubt that that latter interpretation is true, but there’s no doubt that this study is powerful evidence against the view that there is an association between MMR and autism. Unfortunately, I fear that all the nails in my local Home Depot would not be enough to keep the zombie of this pseudoscience from rising from its grave yet again.
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Ever since I first discovered the anti-vaccine movement, first on Usenet, specifically on a Usenet newsgroup devoted to discussing alternative medicine (misc.health.alternative, or m.h.a. for short) and then later on web and on blogs, there have been two things that have horrified me. First, there are the claims that children suffer all sorts of harm from vaccines, be it being made autistic (with the attendant “autism epidemic” caused by vaccines), suffering neurological damage, immune system damage, and all manner of other adverse consequences. There is no good evidence for these claims (although, as has been documented right here on this very blog time and time again, anti-vaccine activists will trot out all manner of awful studies to support their contentions), but that doesn’t keep useful celebrity idiots like Jenny McCarthy, Jim Carrey, Don Imus, or Bill Maher from repeating the same myths over and over again. Worse, the permeation of society with these myths about vaccines has led to declining vaccination rates and the resurgence of potentially deadly vaccine-preventable diseases. It began first in the U.K. in the wake of Andrew Wakefield’s trial lawyer-funded, incompetent, and possibly fraudulent “research,” and has spread to the U.S., thanks to Jenny McCarthy and her ilk, who won’t take responsibility for their words and actions.

Even worse, the myth that vaccines cause autism has led to ideas. Dangerous ideas, and not because they “challenge” medical orthodoxy. These ideas are dangerous because they have direct consequences for children with autism. These consequences take the form of subjecting children to unscientific treatments that are ineffective at best and harmful at worst, sometimes even life-threatening. Indeed, I have written about case histories in which children were subjected to injections of “stem cells” into their cerebrospinal fluid by lumbar puncture and various other “treatments,” as well as chemical castration in combination with chelation therapy. That latter bit of quackery is something I wrote about years ago, but that the mainstream press only just noticed earlier this year. Better late than never, I guess. Even better than that, though, the same reporting team at the Chicago Tribune that reported on Mark and David Geier’s advocacy of Lupron to treat autistic children back in May. Sadly, the result of that story does not appear to have been actions by the State of Maryland to take away Dr. Mark Geier’s medical license or to go after his son David for practicing without a license. Neither does it appear to have resulted in insurance companies going after them for prescribing an expensive drug for an indication for which it is not appropriate. What it does appear to have done, however, is to inspire the same journalist, Trine Tsouderos, along with another journalist from the Chicago Tribune, Patricia Callahan, to pursue an even bigger target that Mark and David Geier, namely the entire “autism biomed movement,” which is for the most part rank quackery, in the following articles:

• Autism treatments: Risky alternative therapies have little basis in science
• Autism treatment: Success stories more persuasive to some than hard data
• Questionable treatments for children with autism

This is another rare case of excellent reporting on this issue, and I hope that this report (another installment of which was published early this morning after I had written this post) will grab the attention of more reporters and news outlets, leading to shining a light on the dark underbelly of the autism biomed movement.
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We’ve written a lot about anti-vaccine zealotry on this blog, as Steve and I take a particular interest in this particular form of dangerous pseudoscience for a number of reasons. One reason, of course, is that the activities of antivaccine groups like Generation Rescue and its spokesmodel since 2007 (Jenny McCarthy, a frequent topic on this blog) have started to frighten parents about vaccines enough that vaccination rates are falling well below that required for herd immunity in some parts of the country. Indeed, McCarthy, at the behest of her handlers in Generation Rescue, serves up a regular “toxic” brew of misinformation and nonsense about vaccines, most recently in a video that was the subject of a post by Val Jones about her unbelievably pseudoscience-laden blather. Truly, it has to be seen to be believed. Meanwhile, Generation Rescue has sent McCarthy on a media propaganda tour for her latest antivaccine pro-quackery book and set up a misinformation-laden propaganda site called Fourteen Studies (blogged about by Steve Novella, Mark Crislip, and, of course, yours truly) in which they attack well-designed studies that have failed to confirm their pet idea that somehow, some way, vaccines must be the cause of autism. And, when their pseudoscience is criticized, the antivaccine movement has a tendency to launch vicious ad hominem attacks, as they recently did against Steve Novella and have done multiple times in the past against me.

However, there is one other consequence of the antivaccine movement, however, and it is at least as important as the public health implications of the potential dimunition of herd immunity caused by the fear mongering of groups like Generation Rescue. That consequence is the cottage industry of “biomedical” treatments to which desperate parents subject their children. Gluten-free diets, chelation therapy (which has caused deaths), hyperbaric oxygen chambers (a recent story described a child getting severely burned when one of these caught fire), autistic children have been subjected to it all. But of all the biomedical woo to which autistic children have been subjected, one form of woo stands out as being particularly heinous. Indeed, I agree with our fearless leader Steve in characterizing it as an “atrocity.”

I’m referring to Mark and David Geier’s favored “treatment” for autistic children, namely a drug called Lupron.
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I have a love-hate relationship with epidemiology.

On the one hand, I love how epidemiology can look for correlations in huge sample sizes, sample sizes far larger than any that we could ever have access to in clinical trials, randomized or other. I love the ability of epidemiology to generate hypotheses that can be tested in the laboratory and then later in clinical trials. Also, let’s not forget that epidemiology is sometimes the only tool available to us that can answer some questions. Such questions generally involve hypotheses that can’t be tested in a randomized clinical trial because of either ethical concerns or others. A good example of this is the question of whether vaccines cause autism. For obvious ethical reasons, it’s not permissible to perform a randomized clinical trial in which one group of children is vaccinated and one is not, and then outcomes with respect to neurodevelopmental outcomes, such as autism and autism spectrum disorders, are tracked in the two groups. The ethical concern with such a study, of course, is the potential harm that would be likely to come to the unvaccinated control group, children who would be left unprotected against common and postentially deadly communicable diaseases.

On the other hand, epidemiology is one of the messiest of sciences, and epidemiological studies are among the most difficult in all of science to perform truly rigorously. The number of factors that can confound are truly amazing, and as a result, it’s very, very easy for an epidemiological study to detect apparent correlations that are either spurious or appear much stronger than the “true” correlation. There can be confounding factors beneath confounding factors wrapped in more confounding factors, the relationships among which are not always apparent. Not infrequently, a condition can appear to be correlated with, for instance, an environmental factor, but in reality that environmental factor and the condition both correlate with a third, unknown confounder. Worse, epidemiologists know that correlation does not necessarily equal causation, but the general public, for the most part, does not, which is why, when anti-vaccine activists, for instance, point out to a rising autism prevalence and then point out that autism prevalence started rising around the same time the vaccine schedule was expanded, to the average layperson the argument sounds compelling. As a result, the design of an epidemiological study is paramount in order to account for or minimize such factors. That’s why I always said I can’t be an epidemiologist. Even though I was very good at math in college, the statistics still made my brain hurt, and I don’t have the patience for the messiness of trying to account for all the possible confounding factors.

However, for all their strengths and flaws, epidemiological studies are an integral part of science-based medicine. They are used to identify predisposing factors to diseases and conditions, environmental contributors to disease, and adverse reactions to drugs, among many other useful pieces of data. That’s why, from time to time, I like to examine epidemiological studies, particularly if they’re epidemiological studies that are getting a lot of press.

The use and abuse of autism epidemiology studies

For instance, studies like this one described in a story in the Los Angeles Times on Friday entitled Proximity to freeways increases autism risk, study finds: More research is needed, but the report suggests air pollution could be a factor:
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