Addressing the ‘too many too soon’ hypothesis

3 Jun

Regular readers may be aware that I blogged about a study recently that demonstrated the early stages of tackling the ‘too many too soon’ hypothesis. It came in for some fierce criticism in the comment section so I wrote to the lead author to get his thoughts. What follows is his answer to me via email:

Reviewing your blog, there are two related criticisms of our study.

First, I must clarify the conflict of interest comment. Though less relevant in my mind, it addresses the other limitations noted by your readers. This study was completely unfunded – not by any pharmaceutical company, not by the CDC. We did this all in our free time because of a simple non-financial “conflict” – as infectious disease physicians we take care of children who suffer needlessly from vaccine preventable diseases. This clarification of funding leads to point 2 – because we
did not have millions of dollars at our disposal we chose to use pre-existing data to address a common parental concern for which we could not find any evidence-based talking points.

This strategy had significant benefits – once we had the idea for this study we got right to work and did not have to wait 7-10 years to see what the outcomes might be. However, as we acknowledge in the discussion (and your readers point out), the use of pre-existing data also introduces limitations. We did not have control over which outcomes were tested, nor which children were included or excluded from the original study.

Nevertheless, I believe this study was accepted for publication in an academic medical journal because it offers a unique methodology that may be used to study the effects of delayed vaccination on any outcome of choice, whether it be the incidence of vaccine-preventable diseases or the proposed vaccine side effect du jour. Unfortunately, I do not have the resources to perform these studies myself.

A separate question – which is really a critique of the original NEJM study (with which I was not involved) and not ours per se – is why the authors chose to exclude the children they did. In the time since you e-mailed be I believe “Luna_the_cat” has explained this fairly clearly. Basically, the original study excluded children with brain injuries that would not have been related to vaccination (except for a few – pneumococcal and haemophilus influenza meningitis which vaccines PREVENT) and this seemed reasonable in the initial study. Furthermore, the majority of these exclusion criteria are prenatal or congenital diagnoses that would have predated vaccination anyway.

Finally, regarding lack of “controls”. This was not a “vaccinated versus unvaccinated” study, nor was it intended to be. It was designed to address the “too many too soon” hypothesis. Our “controls” were those children in the cohort who received fewer vaccines later during the first year of life. In this case the “exposure” was timely vaccine receipt – which was never associated with any adverse neurodevelopmental outcomes.

5 Responses to “Addressing the ‘too many too soon’ hypothesis”

  1. Science Mom June 4, 2010 at 14:03 #

    Thank you Kev for following up and I also thank Dr. Smith for his response. It does clarify some points that will undoubtedly come up whenever this study is referenced.

  2. daedalus2u June 4, 2010 at 14:21 #

    I think the comment on conflict of interest the author is referring to is the eletter comment (which in my opinion is disingenuous)

    http://pediatrics.aappublications.org/cgi/eletters/peds.2009-2489v1

    left by Lawrence D. Rosen,

    http://www.wholechildcenter.org/whowearerosen.html

    who happens to be highly involved an in anti-vaccine organizations (the Deirdre Imus Environmental center)

    http://www.dienviro.com/index1.aspx?BD=18841

    They claim to not be anti-vaccine, but pro safe vaccine, but have no suggestions as to what a safe or green vaccine would be, other than safe and green. Their schedule recommends no more than one vaccination per office visit. Not surprisingly, this approach leads to greater fees for office visits. Conveniently those fees have been posted, and his practice is out of network for all insurance.

    Click to access 2010%20Fee%20Schedule%20-%20Patients.pdf

    Yet Dr Rosen declares no conflict of interest in his evidence-free trashing of a study showing no benefit to spreading out vaccinations over time the way he recommends and which increases his income.

    I think he should have disclosed that he recommends no more than a single vaccination per office visit and that his recommended schedule results in greater office visit fees than does the standard vaccination schedule being tested.

    It really is hard to evaluate his biases. If he has some data that spreading out vaccines results in better outcomes, lets see it. If he doesn’t, then he should disclose that he makes more money by spreading out vaccinations.

  3. daedalus2u June 4, 2010 at 14:24 #

    I think the comment on conflict of interest the author is referring to is the eletter comment (which in my opinion is disingenuous)

    http://pediatrics.aappublications.org/cgi/eletters/peds.2009-2489v1

    left by Lawrence D. Rosen,

    http://www.wholechildcenter.org/whowearerosen.html

    who happens to be highly involved in an anti-vaccine organization (the Deirdre Imus Environmental center)

    http://www.dienviro.com/index1.aspx?BD=18841

    They claim to not be anti-vaccine, but pro safe vaccine, but have no suggestions as to what a safe or green vaccine would be, other than safe and green. Their schedule recommends no more than one vaccination per office visit. Not surprisingly, this approach leads to greater fees for office visits. Conveniently those fees have been posted, and his practice is out of network for all insurance.

    Click to access 2010%20Fee%20Schedule%20-%20Patients.pdf

    Yet Dr Rosen declares no conflict of interest in his evidence-free trashing of a study showing no benefit to spreading out vaccinations over time the way he recommends and which increases his income.

    I think he should have disclosed that he recommends no more than a single vaccination per office visit and that his recommended schedule results in greater office visit fees than does the standard vaccination schedule being tested.

    It really is hard to evaluate his biases. If he has some data that spreading out vaccines results in better outcomes, lets see it. If he doesn’t, then he should disclose that he makes more money by spreading out vaccinations.

  4. daedalus2u June 4, 2010 at 14:25 #

    There is an eletter comment which trashes the study based on conflict of interest (I think disingenuously). I left a comment with 4 links, but it doesn’t seem to be going through.

Trackbacks/Pingbacks

  1. Tweets that mention Addressing the ‘too many too soon’ hypothesis: Regular readers may be aware that I blogged about a st... -- Topsy.com - June 3, 2010

    […] This post was mentioned on Twitter by Kev, Catherina+ScienceMom. Catherina+ScienceMom said: RT @kevleitch Autism Blog – Addressing the ‘too many too soon’ hypothesis « Left Brain/Right Brain http://bit.ly/91froy […]

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