EpiWonk schools David Kirby in epidemiology so that Orac doesn’t have to

At this stage of the game, I almost feel sorry for David Kirby.

Think about it. He’s made his name and what little fame he has (which isn’t much outside of the tinhat crowd that thinks the guv’mint is intentionally poisoning their children with vaccines to make them all autistic) almost entirely on the basis of one book published over three years ago, Evidence of Harm: Mercury in Vaccines and the Autism Epidemic: A Medical Controversy. Of course, the question of whether mercury from the thimerosal preservative that used to be in vaccines, or vaccines themselves, cause autism has not been a medical controversy for some time now. In reality, it’s a “manufactroversy,” in which profit or, in this case, ideology lead to activists sowing confusion or pseudoscience when the science is not seriously in dispute. This leads to an appearance of a scientific controversy where no scientific controversy in fact exists. Whether vaccines cause autism is an excellent example, as is the claim that HIV does not cause AIDS or the effort of “intelligent design” creationists to poke nonexistent holes in the theory of evolution in their unending effort to infiltrate the public schools with religion-inspired pseudoscience.

In the three years since the publication of his book and the subsequent infamous article in Salon.com and Rolling Stone by Robert F. Kennedy, Jr. (which, by the way, was published almost exactly three years ago today) that was so full of misinformation, misrepresentation, and pseudoscience that it astounded me as a new skeptical blogger, David Kirby became, at least before the “rise” of Jenny McCarthy, the chief spokesperson and apologist for the line that mercury somehow causes autism. Undaunted by the accumulation of evidence that put this idea (I will no longer dignify it by calling it a hypothesis) to rest and apparently realizing that his shifting of goalposts was becoming increasingly pathetic, in the last year or so, he’s pivoted effortlessly to the “Green Our Vaccines” strategy. Even so and despite the fact that he’s finally dropped the pretense of being a serious journalist and joined up with the merry band of tinfoil hat conspiracy theorists over at Age of Autism, Kirby still doesn’t appear to be entirely down with the new antivaccinationist regime yet, given that this bunch forgets pharmacology, chemistry, and even common sense in blaming “TOXINS!” in our vaccines for autism. Of course, Kirby did the same thing with his mercury-autism conspiracy-mongering; he was just better at burying the pseudoscience and logical fallacies under a pile of plausible-sounding verbiage. I suspect the reasons that Kirby isn’t quite down with the whole “toxins” thing are two-fold: First, doing so would be an admission that his book was a pile of fetid, stinking crap. Second, I think he’s actually intelligent enough to realize what a supremely, laughably stupid gambit the whole “toxins” bit is, especially when scientific ignoramouses like Kent Heckenlively go so far as to mention that there’s–gasp!–sucrose in vaccines (the horror, the horror!), and useful celebrity idiots like Jenny McCarthy and Jim Carrey parrot the lie that there’s antifreeze in vaccines.

All of this, of course, is my characteristically long-winded introduction to David Kirby’s latest bit of sophistry published on that house organ of antivaccinationism, The Huffington Post, and entitled CDC: Vaccine Study Design “Uninformative and Potentially Misleading.” There’s so much wrong there that I’m profoundly grateful to EpiWonk for taking the time to decontruct David Kirby’s usual blather in detail in a rejoinder called David Kirby: HuffPost Report on CDC’s Vaccine Safety Datalink Uninformative and Completely Misleading

I don’t plan on going into detail into the idiocy published by David Kirby that EpiWonk revealed because she did such a good job at cutting through Kirby’s arrogant ignorance. I do, however, want to add one little bit here. One thing I’ve noticed over the last three years or so that I’ve been in the trenches against antivaccinationists in the blogosphere is that antivaccinationists love to attack the Verstraeten study as though it’s the be-all and end-all of the evidence failing to find a link between mercury in vaccines and autism. The reason, of course, is because this is the time-dishonored technique of the crank: To attack older studies that have flaws as though they are the final word and ignore all the other evidence published subsequently that lacks the flaws of that one study. The Verstraeten study also has a number of features unrelated to the study that make it perfect for conspiracy-mongers. Indeed, Kirby parrots some of them, pointedly referring to the study’s lead author as “Dr. Thomas Verstraeten, an employee of vaccine maker GlaxoSmithKline,” because Verstraeten subsquently took a job with GSK. The other reason is because the study started out appearing to show a strong correlation between mercury in vaccines and autism but in subsequent analyses the effect decreased and ultimately disappeared in the final study: Of course, anyone who’s ever done studies knows that early “off the cuff” analyses often appear to demonstrate effects that don’t pan out under further more rigorous analyses. The other point to be considered is that the reason ecological analyses are not to be trusted is that they are very prone to false positives; i.e., finding correlations where none exist. That subsequent analyses that better controlled for this tendency reduced the original “effect” to noise should not be particularly surprising. None of this is usually evidence of any sort of coverup, but to the more conspiracy-minded who don’t understand science or epidemiology it can appear that way.

In any case, the Verstraeten study may have many flaws, but contrary to what Kirby says, it was not the be-all and end-all of the Institute of Medicine’s 2004 report that concluded that there was no good evidence for a correlation between mercury in vaccines in autism. A number of other studies were also cited. Another point to consider is this question: Why is Kirby harping on this particular study in 2008, five years after its final iteration hit the press? There have been multiple studies subsequent to this that did not rely on the VSD (for example, this Canadian study) and found no correlation between thimerosal or vaccines and autism and one very rigorous study that did use the VSD but used individual-level analyses rather than an ecological analysis to find no correlation between thimerosal or vaccines and neurodevelopmental disorders other than autism. (The followup study on autism is still in progress and should be published in the next year or two.)

Perhaps “Dr.” Kirby would like to analyze the shortcomings of those studies and tell us why their conclusions of no association are unwarranted.

What’s most rich about Kirby’s post is that in his eagerness to look at a reasonable analysis of the pitfalls of ecological (or group-level) analysis of a database like the VSD, he’s thrown poor Mark & David Geier under the bus. Kirby harps on how prone to confounding ecological analyses are (for an explanation of what an ecological analysis is, go here), and in this EpiWonk agrees 100%. The problem is that Mark & David Geier’s latest crapfest of a paper that was recently published is–you guessed it!–an ecological analysis of the VSD database.

The irony is beautiful.

I’ll conclude with what is perhaps the best characterization of Kirby when it comes to epidemiology, courtesy of EpiWonk:

Fortunately, I taught epidemiologic design and methods for about 35 years, I had some students almost as clueless as David Kirby, but I’m a patient teacher. Another interesting fact is that there has only been one ecologic study published using the VSD, and I’ve written extensively about the study on this blog. Guess what? It wasn’t done by the CDC, who knew better long before the 2006 NIEHS Expert Panel. I’m speaking of the infamous Young-Geier Autism Study.

EpiWonk may be a patient teacher, but the student has to want to learn for a teacher to have any chance whatsoever of success. I have yet to see any evidence from Mr. Kirby that he wants to learn anything at all that might threaten his belief that it really, truly was the mercury after all.