CDC: Vaccine Study Design "Uninformative and Potentially Misleading"

News from Health Lover, Ilena Rosenthal:
http://ilenarose.blogspot.com



EXCERPT: CDC officials conducted at least five separate analyses of
the data over a four-year period from 1999-2003. The first analysis
showed that children exposed to the most thimerosal by one month of
age had extremely high relative risks for a number of outcomes,
compared with children who got little or no mercury: The relative risk
for ADHD was 8.29 times higher, for autism, it was 7.62 times higher,
ADD, 6.38 times higher, tics, 5.65 times, and speech and language
delays were 2.09 more likely among kids who got the most mercury.

~~~~~~~~~~~~~~
Bravo to David Kirby and all vaccination awareness activists!

To see him insulted by disbarred Snake-oil attorneys and corporate
lobbyists ... tells so much about their level of desperation. They
profit from selling the Vaccination industry propaganda. Watching them
stumble about as their cover-up uncovers is quite pitiful.

www.BreastImplantAwareness.org/Snake-oil.htm
http://www.BreastImplantAwareness.or...WatchWatch.htm

http://www.huffingtonpost.com/david-..._b_108398.html

CDC Director Dr. Julie Gerberding has delivered a potentially
explosive report to the powerful House Appropriations Committee, in
which she admits to a startling string of errors in the design and
methods used in the CDC's landmark 2003 study that found no link
between mercury in vaccines and autism, ADHD, speech delay or tics.

Gerberding was responding to a 2006 report from the National Institute
of Environmental Health Sciences (NIEHS), which concluded that the
CDC's flagship thimerosal safety study was riddled with "several areas
of weaknesses" that combined to "reduce the usefulness" of the study.

"CDC concurs," Dr. Gerberding wrote in an undated mea culpa to
Congress, (provided to me through a Capital Hill staffer) adding that
her agency "does not plan to use" the database in question, the
Vaccine Safety Datalink, (VSD) for any future "ecological studies" of
autism.

In fact, Gerberding's report said, any continued use of the VSD for
similar ecological studies of vaccines and autism "would be
uninformative and potentially misleading."

Ecological vaccine studies are large, epidemiological analyses of
risks and trends using computerized data from large populations -- in
this case children enrolled at several big HMOs -- without ever
examining a single patient in person.

CDC officials conducted at least five separate analyses of the data
over a four-year period from 1999-2003. The first analysis showed that
children exposed to the most thimerosal by one month of age had
extremely high relative risks for a number of outcomes, compared with
children who got little or no mercury: The relative risk for ADHD was
8.29 times higher, for autism, it was 7.62 times higher, ADD, 6.38
times higher, tics, 5.65 times, and speech and language delays were
2.09 more likely among kids who got the most mercury.

Over time, however, all of these risks declined into statistical
insignificance, statistical inconsistency or else outright oblivion:
The relative risk for autism plummeted from 7.62 in the first
analysis, to 2.48 in the second version, to 1.69 in the third round,
to 1.52 in the fourth, and down to nothing at all in the fifth, final,
and published analysis printed in the Journal Pediatrics in November
of 2003.

Vaccine officials attributed the steady drop to the elimination of
"statistical noise" from the data through due diligence and the
endeavor for excellence in governmental statistical analysis.

Indeed, the VSD study was the main pillar of a hugely influential 2004
report by the Institute of Medicine, which also concluded that there
was no evidence of link between mercury, vaccines and autism.

To this day, public health officials routinely point to five "large
epidemiological studies" representing the "highest quality science,"
none of which found any link to thimerosal.

In fact, the American VSD study has long been held up as the best and
brightest of them all (the others were in Sweden, the UK, and two in
Denmark). And this reputation has stuck in the minds of medicine and
the media.

Curiously though, even the study's lead author -- Dr. Thomas
Verstraeten, an employee of vaccine maker GlaxoSmithKline -- protested
that the VSD study "found no evidence against an association, as a
negative study would. In fact, he said that additional study was
needed, which "is the conclusion to which a neutral study must come."

That's when Congress stepped in.

In 2005, a group of Senators and Representatives headed by Sen. Joe
Lieberman wrote to the NIEHS (an agency of the National Institutes of
Health) saying that many parents no longer trusted the CDC to conduct
independent minded studies of its own vaccine program. Lieberman et al
asked NIEHS to review the CDC's work on the vaccine database and
report back with critiques and suggestions.

The final NIEHS report was a serious and thoughtful critique of where
the CDC went wrong in its design, conduct and analysis of the study.
The NIEHS panel "identified several serious problems," with the CDC's
effort, criticism to which the agency had not responded -- until now.

In her letter to the House Appropriations Committee, the CDC Director
responded directly to many -- though not all -- of the most important
criticisms and recommendations contained in the NIEHS panel report.

For example, the NIEHS had criticized CDC for failing to account for
other mercury exposures, including maternal sources from flu shots and
immune globulin, as well as mercury in food and the environment.

"CDC acknowledges this concern and recognizes this limitation," the
Gerberding reply says.

The NIEHS also took CDC to task for eliminating 25% of the study
population for a variety of reasons, even though this represented, "a
susceptible population whose removal from the analysis might
unintentionally reduce the ability to detect an effect of thimerosal."
This strict entry criteria likely led to an "under-ascertainment" of
autism cases, the NIEHS reported.

"CDC concurs," Gerberding wrote, again noting that its study design
was "not appropriate for studying this vaccine safety topic. The data
are intended for administrative purposes and may not be predictive of
the outcomes studied."

Another serious problem was that the HMOs changed the way they tracked
and recorded autism diagnoses over time, including during the period
when vaccine mercury levels were in decline. Such changes could
"affect the observed rate of autism and could confound or distort
trends in autism rates," the NIEHS warned.

"CDC concurs," Dr. Gerberding wrote again, "that conducting an
ecologic analysis using VSD administrative data to address potential
associations between thimerosal exposure and risk of ASD is not
useful."

Read that sentence one more time. The head of the CDC is saying that
its most powerful and convincing piece of exonerating evidence for
thimerosal is, in effect, "useless."

I hope everyone will read it, including the recommendations to make
the VSD better, and the CDC's agreement with all of the suggestions.

As questionable at the US thimerosal study was, "it was an improvement
on other studies, including the two in Denmark, both of which had
serious weaknesses in their designs," Dr. Irva Hertz-Picciotto,
Professor of Public Health at UC Davis Medical School and Chair of the
NIEHS panel, told reporter Dan Olmsted at UPI.

That leaves very little for the CDC to go on in terms of proving that
thimerosal and autism are not associated in any way.

Yes, there is always the study of disability services data from
California -- which seem to be rising among the youngest cohorts of
kids, who presumably received little or no mercury because thimerosal
was largely removed from childhood shots.

But California is an "ecological study" with problems of its own.

"Although (this) information is often used by media and research
entities to develop statistics and draw conclusions, some of these
findings may misrepresent the quarterly figures," cautions the website
of the California Department of Developmental Services (DDS).
"Increases in the number of persons reported from one quarter to the
next do not necessarily represent persons who are new to the DDS
system."

Even the CDC admits that "there are several limitations" with linking
a VSD study design with the California data, Gerberding wrote to
Congress, because, among other things, California only counts "persons
who were referred to and/or voluntarily entered" the disability
system."

It will be interesting to see how the House Committee -- and the
mainstream media -- react to this rather breathtaking confession by
the CDC, which does seem to want to conduct the best vaccine-autism
science possible (see Gerberding's replies to NIEHS recommendations
for improving the VSD: CDC officials are currently conducting in-
depth follow up studies with VSD patients).

As the waning months of the Bush administration get underway, I can't
help but wonder if a little housecleaning might be going on at some of
our top health agencies.

(And on that note, please see my blog about the upcoming
HHS/FDA/CDC/NIH workshop on autism triggers in mitochondrial disorders
(ie, Hannah Poling and her five vaccines).