correction:
As noted in the comments below, Mr. Kirby appears to be basing argument suggesting that the Hepatitis B vaccine could have caused autism on ADDM data, not on the NSCH dataset, as I assumed.
A recent blog post on the Huffington Post contains serious errors and should be edited or pulled. At the very least a public acknowledgment of the error must be made.
Using data from the recently published 2007 National Survey of Children’s Health to estimate autism prevalence, a Huffington Post blogger (David Kirby) attempted to draw a connection between the Hepatitis B vaccine and an “explosion” of autism . Here is what he wrote:
If there is an environmental component to autism, hopefully scientists will want to know which exposures might have increased between, say, 1992 and 1996.
One possible answer is the Hepatitis B vaccine, (which also contained 25 micrograms of mercury containing thimerosal).
Introduced in 1991, it was the first vaccine ever given on a population basis to newborn babies (within the first three hours after delivery) in human history.
But according to the CDC’s National Immunization Survey (which also includes parental telephone interviews), only 8% of infant children received the Hep B vaccine in 1992, when that birth cohort showed an ASD rate of 60-per-10,000.
By 1994, the number of children receiving Hep B vaccine had reached just 27% — and the cohort showed an ASD rate of 66-per-10,000.But the Hep B coverage rate had risen to 82% by 1996, when that cohort’s ASD rate exploded to around 100-per-10,000.
Correlation, obviously, does not equal causation. And no one is suggesting that Hepatitis B vaccine is the singular “cause” of autism. But the uptake rate of that particular immunization is at least one environmental factor that did demonstrably change during the period in question.
Emphasis is mine. I emphasized the data which are the data that are incorrect.
The analysis is simple. Here are the actual results compared to what Mr. Kirby misreported:
1992 “birth cohort*”:
102 per 10,000 (not 60 per 10,000 as on HuffPo)
1994 “birth cohort*”:
113 per 10,000 (not 66 per 10,000 as on HuffPo)
1996 “birth cohort*”:
111 per 10,000 (close to the “around” 100 per 10,000 quoted).
Or, to put it very simply: Mr. Kirby’s statement that there was an “explosion” in the autism rates is incorrect. The evidence that the introduction of the Hepatitis B vaccine is somehow related to the increase in autism rates is false.
That entire statement isn’t even a misinterpretation–it is just simply, demonstrably, false.
Unfortunately, this isn’t Mr. Kirby’s first clear and serious error. He has a history of mistakes. Unfortunately, he doesn’t have a history of correcting his mistakes. Consider these examples:
In June 2008, epiwonk publish a blog post “David Kirby: HuffPost Report on CDC’s Vaccine Safety Datalink Uninformative and Completely Misleading“, demonstrating clear errors in Mr. Kirby’s post “CDC: Vaccine Study Design “Uninformative and Potentially Misleading“”.
The errors were serious enough that Mr. Kirby rewrote his blog post as CDC: Vaccine Study Used Flawed Methods. This included the following introduction:
NOTE: My original post on this topic mischaracterized the 2003 CDC vaccine investigation as an “Ecological Study,” which it was not. I am reposting this piece to reflect that information accurately, but also to point out that many of the weaknesses identified in the CDC’s data and methods apply to the published 2003 “retrospective cohort” study, as much as they do to any future “ecological” ones. I regret and apologize for the error.
Mr. Kirby “regrets” and “apologizes” for the error. Yet his original, erroneous blog post is still on the Huffington Post website. He never took it down. He didn’t even add an apology or correction note to the piece. Anyone following a link to it would have no idea that even the author acknowledges the serious flaws in that piece.
It is also worth noting that the “corrected” version of Mr. Kirby’s blog post was also in error. Again, as noted by epiwonk, this time in his piece “David Kirby HuffPost, Take 2: My Original Story was Flawed, So Here’s A Second (”Corrected”) Story That’s Still Flawed, But I Hope I Can Snow You Under Again This Time…”
Mr. Kirby compounded this error when he recreated it in his first “congressional briefing”, September 2008. Mr. Kirby misquoted a report by the National Institute of Enviornmental Health Sciences, and he was caught by a knowledgeable staffer.
Again, Mr. Kirbty has failed to correct his error. He posted his power point presentation to his website, but without any acknowledgment of the error on page 6. In the transcript for this talk, he only states, “NOTE: This statement omits important details of the CDC response” and sends you to other sites “For a more detailed explanation”. The “transcript” makes no reference to the exchange between Mr. Kirby and the congressional staffer, nor does it acknowledge that the omission was critical to the point being made. The transcript is noted as being a “Rush transcription by Nancy Hokkanen”. Being in a rush is not an excuse to leave important flaws unexplained.
Math errors are also not new to Mr. Kirby. In May 2008, Mr. Kirby wrote a piece analyzing data from Scotland. In doing so, Mr. Kirby misread a graph resulting in a factor of 10 error in a key piece of information (he misread a bar graph . After his error was blogged, Mr. Kirby corrected his Huffington Post piece. What he didn’t do, and he should have, was to note in the blog piece that he made the error and corrected it.
Mr. Kirby placed his Scotland data post in two sites: Huffington Post and the Age of Autism blog. In yet another odd move by Mr. Kirby, he left the original version of his post, complete with the factor of 10 error, on the Age of Autism blog (it still has 34,000 instead of 3,400). As noted above, Mr. Kirby obviously knows about the error, since he corrected it on the Huffington Post.
Since he clearly knew that his post on the Age of Autism blog had a big error, why didn’t he make a correction (with acknowledgment of the error) there?
Mr. Kirby had a bit of a problem with understanding the difference between Change.Org Change.Gov (the Obama transition team’s website) and Change.Org (a website that hosts blogs on important topics, including autism) (also noted here and here) He made a clear correction on the Huffington Post. However, his post on the Age of Autism blog just disappeared without a comment.
But let’s get back to the present. Mr. Kirby has blogged erroneous data and used this to show a false correlation between the Hepatitis B vaccine introduction and the rise in autism rates.
In case anyone is thinking, “are you sure you checked your own numbers, Sullivan?” The answer is yes. I double checked. I asked a frequent commenter on this blog, Dawn, to check my numbers. Another commenter independently collected and graphed the NCSH data as well. No evidence for an “explosion” of autism rates. Take a look at the graph. Mr. Kirby claimed that the 2007 survey data showed autism rates of about 60/10,000 for kids aged 13 and 15. There are no rates below 80 per 10,000 for the kids in those age ranges in that dataset.
So here we have a man with a history of errors, and with a history of failing to adequately correct his errors. He now has a new, big, obvious error. This error is likely the most serious of those listed here, in my opinion. Mr. Kirby has convinced people that the Hepatitis B vaccine could be causing autism. That was a serious accusation, and it was wrong. The question before us now is this: what will Mr. Kirby do now that he knows he made a mistake?
I’m very curious about that, so I’ve emailed Mr. Kirby and one of the editors at the Huffington Post with this information. I’ll let you all know what I hear back.
*note: the NSCH data are not given as “birth cohorts”. Instead, they are given by age. The survey was performed in 2007 and 2008. So, the 15 year old age group is roughly the “1992 birth cohort”. Likewise, 13 year olds are the 1994 “cohort” and 11 year olds are the 1996 “cohort”.
EDIT: Note that I too have a problem with keeping Change.Org and Change.Gov separate. This correction was made after the post was published.
Recent Comments