Uh-oh. |
However, 10 years after the initial study was conducted, famous anti-vaccine alarmist Brian Hooker, along with Andrew Wakefield, are talking about a "whistleblower" in the CDC claiming that the original data was fraudulent, and was masking a 336% increased risk in ASD in African American boys receiving the MMR vaccine "on time." Hooker published his own findings in the Journal of Translational Neurodegeneration, titling it Measles-mumps-rubella vaccination timing and autism among young african american boys: a reanalysis of CDC data. He claims that according to the "whistleblower," Dr. William Thompson, the CDC intentionally manipulated the data to bury this increased risk.
Here we go again. |
But what exactly is going on here? Was the CDC fraudulent? Did they intentionally manipulate the data to hide this increased risk? Before we get to that, there are a few things we need to make note of.
It's always good to remain skeptical when someone proposes that they have reanalyzed already published data. In my experiences, although limited, this never amounts to anything good, and the arguments are usually pretty weak. On that same note, when someone reanalyzes data, they most likely have a chip on their shoulder. Keep in mind this isn't true for all reanalyses -- in fact, such reanalysis is what called Wakefield out for his fraudulence in the first place -- but I'm speaking from personal experience.
These a priori contentions not withstanding, Hooker's reanalysis just didn't seem right at all when I first looked at it. Let's just quote the conclusions from the abstract for a moment:
"The present study provides new epidemiologic evidence showing that African American males receiving the MMR vaccine prior to 24 months of age or 36 months of age are more likely to receive an autism diagnosis."And from the results:
"Relative risks for males in general and African American males were 1.69 (p=0.0138) and 3.36 (p=0.0019), respectively."Hooker went through all this trouble just to show that only African American males are at a higher risk for ASD from the MMR jab? That's certainly not going to do anything for Jenny McCarthy. Color me unimpressed by the so called coverup by the CDC, because it leaves the overwhelming majority of evidence that shows there is no link between the MMR vaccine and ASD untouched. In fact, even if he'd shown the whole study was fraudulent from its conception, he still would've left the overwhelming majority of research to the contrary untouched. Even better, a 3.36 increase in ASD isn't 336%. It's 236%.
Booker accuses DeStefano et al. (2004) of intentionally leaving out African American males in their sample in order to manipulate the results, but that's just not what happened. Subjects that were inappropriate, given age requirements and necessity of medical information, were excluded from the study because they wouldn't be able to control for the important things mentioned earlier: maternal and birth factors, as well as actually comparing something useful in this particular study. DeStefano et al. weren't manipulating the data, they were legitimizing it.
But the burning question here is: did Hooker even manage to show what he claimed he did? Are African American males at a higher risk for ASD from the MMR jab at ages younger than 24 or 36 months? Let's take a look inside the paper to find out.
"The relationship between the MMR vaccine and autism was first hypothesized by Wakefield et al. [7] in 1999 after the observation of a regressive phenotype of autism that appeared in general after the administration of the first MMR vaccine. Although several studies have affirmed such a relationship between the MMR vaccine and neurodevelopmental disorders including autism [8,9], many other studies purport no statistical relationship between the MMR vaccine and autism incidence."This is only the third paragraph in, mind you, and Hooker cites Wakefield, and then two studies by the Geier duo. Don't make me laugh. Hooker is partaking in a classic "teach the controversy" grasp at straws to make it seem like there's even some doubt that the MMR vaccine isn't linked to ASD. No matter. Let's just skip to the methodology:
"Cohort data were obtained directly as a “restricted access data set” from the Centers for Disease Control and Prevention (CDC) via a Data Use Agreement. Data were deidentified by the CDC in accordance with Family Education Rights and Privacy Act (FERPA) and the Health Insurance Portability and Accountability Act (HIPAA) prior to receipt by the study authors."Wait what? Cohort data? But the original study by DeStefano et al. was case-control. Oh, there we see it.
I know I have some readers who aren't too fond of statistical babble, so I'll sum up what the issue is here. The original study by DeStefano et al. used something called a case-control model. In a case-control model, you compare a group of case subjects (subjects with the disease) and control subjects (without the disease) and determine how frequently another variable occurs for either group of subjects while controlling for confounders and effect modifiers. Hooker, on the other hand, used a cohort model, which doesn't quite do the same thing. Regardless, using data that was arranged to be analyzed in a case-control model and then analyzing it in a cohort model is just screaming problems; especially when you chop up the data into multiple subcohorts so that any small effect will be magnified.
The funny thing is, even with the skewed methodology, the results aren't even impressive. Table 2 below from Hooker's paper shows the age group cutoffs and their risk for ASD:
So what's wrong here? Not much, except for the fact that the relative risk only sees a modest increase at the 24 month cutoff. The true increase is seen at 36 months. So why is this important? Because symptoms of autism are most noticeable starting at age 3. This isn't anything new Hooker. That's why DeStefano et al. controlled for age in their original study. Because they're not stupid.
But why was there an increase in exclusively African American male children? The answer is simple again. Table 4 from the study shows us this:
Hooker reveals that he had to use a 31 month cutoff because he was limited in terms of sample size. This, also, isn't anything new in the realm of statistics, Hooker. Smaller sample sizes are going to potentially yield misleading results because the smaller the sample, the greater its susceptibility to statistical noise. Funny enough, Hooker didn't even provide his sample size. The very lack of transparency in Hooker's paper, after being prompted by accusations of a lack of transparency in the CDC, is absolutely egregious.
This didn't take very long to research and debunk; in fact, I was surprised at how little exposure this study got. Perhaps we're all learning something from these types of studies: they provide nothing informative, and are only reflections of someone's ideologically grinding teeth and hand waving. In doing so, Hooker hooked a hoax: his own.
Thank you all very much for reading.
UPDATE: Translational Neurodegeneration has taken Hooker's article off public domain for concerns about the validity of its findings. You can find it in full here.
(8/28/2014) Yesterday, Dr. Thompson released a statement via his lawyers clearing the air of any doubts: Wakefield is just as disingenuous and manipulative as he's always been.
(10/3/2014) Brian Hooker's paper was retracted from the journal of Translational Neurodegeneration after concerns were expressed of its validity. The PubMed link still works.
*I would also highly recommend looking at this infographic from Healthcare Management Degree.
Sources are at the bottom of the page.*
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References:
DeStefano, F., Bhasin, T., Thompson, W., Yeargin-Allsopp, M., & Boyle, C. (2004). Age at First Measles-Mumps-Rubella Vaccination in Children With Autism and School-Matched Control Subjects: A Population-Based Study in Metropolitan Atlanta. PEDIATRICS, 113 (2), 259-266 DOI: 10.1542/peds.113.2.259
Hooker, B. (2014). Measles-mumps-rubella vaccination timing and autism among young african american boys: a reanalysis of CDC data. Translational Neurodegeneration, 3 (1) DOI: 10.1186/2047-9158-3-16