Several people have been sending me either links to this paper or even the paper itself:
Young HA, Geier DA, Geier MR. (2008). Thimerosal exposure in infants and neurodevelopmental disorders: An assessment of computerized medical records in the Vaccine Safety Datalink. J Neurol Sci. 2008 May 14 [Epub ahead of print]. (Full text here.)
Some have asked me whether I was planning on deconstructing it, given that the mercury militia has apparently been promoting it as "evidence" that it really, truly, and honestly was the mercury in vaccines after all that caused autism. I did mention it about three weeks ago, but I really didn't do a full deconstruction because I didn't need to. A new blogger called EpiWonk did a three part take-down that eviscerated this latest bit of "science" from Geier père et fils so thoroughly and with a much greater knowledge of epidemiology than I could ever muster, that I saw no need. However, since this study appears to be rearing its ugly head again, it's worth directing you to EpiWonk's three-part take-down. I had been meaning to to this anyway, but had gotten side-tracked by numerous other topics. To make up for my lapse, here we go:
- New Study on Thimerosal and Neurodevelopmental Disorders: I. Scientific Fraud or Just Playing with Data?
- New Study on Thimerosal and Neurodevelopmental Disorders: II. What Happened to Control for Confounding?
- New Study on Thimerosal and Neurodevelopmental Disorders: III. Group-Level Units of Analysis and the Ecological Fallacy
Enjoy! And the next time an antivaccinationist points to this particular study, send 'em over to see EpiWonk. Tell 'em Orac sent you.
What's the take on J Neurol Sci? Are their peer-review procedures faulty or something?
I read through all of EpiWonk's posts on the subject when Orac had originally pointed to them -- good stuff! If you haven't checked them out yet and the topic is of interest to you, I heartily encourage you to take the time to read them.
And thanks to Orac for the pointer to another good science blogger. EpiWonk as been added to my list of blogs-to-check-in-on-regularly.
"And the next time an antivaccinationist points to this particular study, send 'em over to see EpiWonk. Tell 'em Orac sent you."
Oh, if only that worked.
The problem with the EpiWonk posts is that they are incomplete. He/she stated up front it would be (at least) a 5 part sequence, and part 3 ended with a look ahead to what would come next in part 4, but no more installments have appeared (3+ weeks out).
Parts 1-3 were general methodological criticisms, and the next installment EpiWonk promised to directly address the numbers that underlie the authors claims.
So at this point, although EpiWonk has pointed out the weaknesses of the study, he/she has yet to show that those weaknesses undercut their conclusions.
Does directing the clue resistant to clues ever work?
Clare,
One of peer-review's greatest weaknesses is that the reviewers are human and thus prone to being influenced by their own biases. Another weakness is that the editor can over-ride the reviewers' recommendations (e.g. "Throw this piece of trash in the dumpster!") and publish the paper anyway.
The lead author (HA Young) has quite a long and impressive publication record, but only one in the area of autism. The publication record may have swayed the reviewers or they may not have realized how shoddy the work was.
We may never know how/why this poor study got published, but it isn't the first poor study to get published (not even in the field of autism) and it won't be the last. The key thing is that poor research is occasionally published - even in peer-reviewed journals. The interesting thing is that so much of the poor "research" on autism has the same names on it.
Prometheus
Prometheus -- thanks and what you say is absolutely true. Also, if editors follow the suggestions of authors as to which readers to contact (happens in some fields, though I don't know if this is the case in ALL fields), that can definitely warp the intent of peer-review. What I wasn't sure about was whether this particular journal was known to have a liking for -- shall we say -- "creative" articles on autism (or indeed on any other subjects they publish on). And if, as you point out, the same names keep popping up on the more wacky autism articles, doesn't word get around? I guess that neuroscience is a large enough field that journal editors may not necessarily know who is "all the way out there" on every topic. But you'd have to have been living under a rock not to know that allegations of a connection between immunizations and autism draw considerable public attention outside the scholarly domain, and I would think you might want to tread a little more carefully as a result.
So at this point, although EpiWonk has pointed out the weaknesses of the study, he/she has yet to show that those weaknesses undercut their conclusions.
The weaknesses noted in Part II clearly undercut their conclusions, even without knowing specifics about the data. During the first part of the 1990s it is well known that the thimerosal dose per child was on an upward trend. So were diagnoses of autism for the corresponding birth cohort.
In fact, the Geiers absolutely knew this. I say this because I've read previous papers of theirs.
Clare,
The Journal of Neurological Science is an established journal with a good reputation. Although the editors may have realized how controversial the topic is, they may not have realized how "controversial" the second and third authors are.
Sometimes, editors will publish a study that is "controversial" or even contrarian simply because they want to provide a forum for "new ideas". It is a foreign concept to most journal editors that the authors may have a purely political (or legal) reason for publishing. And, as I mentioned above, most editors rather naively assume that the authors are at least trying to do good science.
The fact that the Geiers continue to get their "studies" published shows how false the accusation that "alternative views and hypotheses can't get published" is. Editors continue to provide them a forum for their flawed "studies" because they aren't "mainstream".
If they were trying to publish yet another study showing that vaccines prevent more death and disability than they have been accused of causing, it would have been much harder to get published. "Controversy" sells scientific journals, too.
Prometheus
Thanks Prometheus -- that makes sense.. although a sad kind of sense.