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John Stone
United Kingdom
1254 Posts |
 Posted - 01/27/2009 : 07:26:21
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http://pediatrics.aappublications.org/cgi/content/abstract/123/2/475
Neuropsychological Performance 10 Years After Immunization in Infancy With Thimerosal-Containing Vaccines
Alberto Eugenio Tozzi, MDa, Patrizia Bisiacchi, PhDb, Vincenza Tarantino, PhDb, Barbara De Mei, DSociolc, Lidia D'Elia, DPsycholc, Flavia Chiarotti, DStatc and Stefania Salmaso, DBiolc
OBJECTIVE. Thimerosal, a mercury compound used as a preservative in vaccines administered during infancy, has been suspected to affect neuropsychological development. We compared the neuropsychological performance, 10 years after vaccination, of 2 groups of children exposed randomly to different amounts of thimerosal through immunization.
METHODS. Children who were enrolled in an efficacy trial of pertussis vaccines in 1992–1993 were contacted in 2003. Two groups of children were identified, according to thimerosal content in vaccines assigned randomly in the first year of life (cumulative ethylmercury intake of 62.5 or 137.5 µg), and were compared with respect to neuropsychological outcomes. Eleven standardized neuropsychological tests, for a total of 24 outcomes, were administered to children during school hours. Mean scores of neuropsychological tests in the domains of memory and learning, attention, executive functions, visuospatial functions, language, and motor skills were compared according to thimerosal exposure and gender. Standard regression coefficients obtained through multivariate linear regression analyses were used as a measure of effect.
RESULTS. Nearly 70% of the invited subjects participated in the neuropsychological assessment (N = 1403). Among the 24 neuropsychological outcomes that were evaluated, only 2 were significantly associated with thimerosal exposure. Girls with higher thimerosal intake had lower mean scores in the finger-tapping test with the dominant hand and in the Boston Naming Test.
CONCLUSIONS. Given the large number of statistical comparisons performed, the few associations found between thimerosal exposure and neuropsychological development might be attributable to chance. The associations found, although statistically significant, were based on small differences in mean test scores, and their clinical relevance remains to be determined.
However, from the main text:
'Some limitations should be considered in the interpretation of our results. The cumulative intake of thimerosal was relatively low, compared with that in other countries including the United States, where vaccination schedules included more thimerosal-containing vaccines in the first year of life. Moreover, there was no comparison group with no exposure to thimerosal, although our setting was appropriate to identify a dose response effect in the absence of any evidence suggesting a threshold dose for observation of an effect. Our analysis included only healthy children who were selected during enrollment in the original trial, and some families might have declined to participate in the present study because their children had cognitive developmental problems. This might have reduced the prevalence of adverse neuropsychological conditions and might have made potential differences hard to detect. The eligibility criteria of the original trial also limited the participation of low birth weight children, and only 55 children with birth weights of <2500 g underwent the neuropsychological evaluation (data not shown). Moreover, only 1% of children in this study received hepatitis B virus vaccine at birth. Although no effect of birth weight according to thimerosal intake was detected through multivariate analyses, our study was not powered to detect an association of thimerosal exposure and neuropsychological development in low birth weight infants.'
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GUS THE FUSS
United Kingdom
1449 Posts |
Posted - 01/27/2009 : 13:57:10
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Feeding the Hungry Lie, Italian Style
http://www.ageofautism.com/2009/01/feeding-the-hungry-lie-italian-style.html#more
By J.B. Handley
Well, you won't be able to miss it because it's all over the news: another "study" published in Pediatrics proving that vaccines don't cause autism.
In case you wonder how the media feels about the whole thing, consider this opening line from the Associated Press article today:
"A new study from Italy adds to a mountain of evidence that a mercury-based preservative once used in many vaccines doesn't hurt children, offering more reassurance to parents."
Mountain of evidence?
Herewith, my guide to reading this new study:
1. Re-read my original post, Feeding the Hungry Lie HERE.
2. Open the new study from Pediatrics, titled:
Neuropsychological Performance 10 Years After Immunization in Infancy With Thimerosal-Containing Vaccines
3. Prepare for Nausea.
Continue reading "Feeding the Hungry Lie, Italian Style" »
http://www.ageofautism.com/2009/01/feeding-the-hungry-lie-italian-style.html#more
MMR RIP |
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GUS THE FUSS
United Kingdom
1449 Posts |
Posted - 01/27/2009 : 20:49:09
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Great response from John
http://pediatrics.aappublications.org/cgi/eletters?lookup=by_date&days=30
This study is misleading and was not scientifically worth doing 27 January 2009
Re: This study is misleading and was not scientifically worth doing
E-mail John Stone
I note the conclusion of this study by Tozzi, Bisiacchi, Tarantino, De Mei, D'Elia, Chiarotti and Salmaso [1]. However, I also note the limitations of the study as described in the discussion:
'Some limitations should be considered in the interpretation of our results. The cumulative intake of thimerosal was relatively low, compared with that in other countries including the United States, where vaccination schedules included more thimerosal-containing vaccines in the first year of life. Moreover, there was no comparison group with no exposure to thimerosal, although our setting was appropriate to identify a dose response effect in the absence of any evidence suggesting a threshold dose for observation of an effect. Our analysis included only healthy children who were selected during enrollment in the original trial, and some families might have declined to participate in the present study because their children had cognitive developmental problems. This might have reduced the prevalence of adverse neuropsychological conditions and might have made potential differences hard to detect. The eligibility criteria of the original trial also limited the participation of low birth weight children, and only 55 children with birth weights of <2500 g underwent the neuropsychological evaluation (data not shown). Moreover, only 1% of children in this study received hepatitis B virus vaccine at birth. Although no effect of birth weight according to thimerosal intake was detected through multivariate analyses, our study was not powered to detect an association of thimerosal exposure and neuropsychological development in low birth weight infants.' [1]
I ask how it would be possible to draw any useful scientific conclusions from a study with such deficiencies in relation to the issues it purportedly set out to investigate? But I also reflect on the headline value of negative results for wider media consumption, as in the Associated Press report by Carla K Johnson, with contributions from Alberto Tozzi himself, Jennifer Pinto-Martin and Paul Offit [2] claiming this strengthens the evidence base for vaccine safety.
[1] Alberto Eugenio Tozzi, Patrizia Bisiacchi, Vincenza Tarantino, Barbara De Mei, Lidia D'Elia, Flavia Chiarotti, and Stefania Salmaso, 'Neuropsychological Performance 10 Years After Immunization in Infancy With Thimerosal-Containing Vaccines', Pediatrics 2009; 123: 475-482.
[2] Carla K Johnson, 'Study adds to evidence of vaccine safety', Associated Press, http://www.google.com/hostednews/ap/article/ALeqM5jp7ZD1RFVm7yOzgaB04Ra4dY_ZuQD95UKPPG0
Conflict of Interest:
Parent of an autistic son
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John Stone
United Kingdom
1254 Posts |
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Aasa
Canada
731 Posts |
Posted - 01/28/2009 : 04:11:10
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Nice going, John, and credit to Mike Wagnitz too, even though I was hoping that he could have written MORE (being a chemist and all). Eagerly awaiting more criticism or "peer review" of this so-called "study". Am sure it will follow in the near future.
Aasa |
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Cybertiger
United Kingdom
976 Posts |
Posted - 01/28/2009 : 09:11:48
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quote:
Originally posted by Aasa
Eagerly awaiting more criticism or "peer review" of this so-called "study". Am sure it will follow in the near future.
Orac, fan of Dr Who????, militant pro-vaccineer and peer of the Blake Seven realm, has already posted his burningly stupid two-tuppence worth.
"The thimerosal hypothesis of autism is dead, dead, dead! This hypothesis is no more! It has ceased to be! It's expired and gone to meet its maker! It's a stiff! Bereft of life, it rests in peace! If the mercury militia wouldn't keep nailing it to the perch it'd be pushing up the daisies! Its metabolic processes are now history! It's off the twig! It's kicked the bucket, it's shuffled off this mortal coil, run down the curtain and joined the bleedin' choir invisibile!! The thimerosal/mercury/autism hypothesis IS AN EX-HYPOTHESIS!!"
http://scienceblogs.com/insolence/2009/01/the_first_of_i_hope_many_very_bad_days_f.php#more
Perhaps 'Orac the insolent' will have the courage of his 'pushing daisy' convictions ... to post a deadly version of his burningly stupid 'death hypothesis' ... to the esteemed readers of the American medical journal 'Pediatrics'. I await with eager anticipation. |
Edited by - Cybertiger on 01/28/2009 10:28:42 |
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John Stone
United Kingdom
1254 Posts |
Posted - 01/28/2009 : 10:10:29
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Mike's letter wasn't up when I posted the link, but I don't think chemistry ever came into it - the study was of perfect bureaucratic design.
quote:
[i]Originally posted by Aasa[/i]
[br]Nice going, John, and credit to Mike Wagnitz too, even though I was hoping that he could have written MORE (being a chemist and all). Eagerly awaiting more criticism or "peer review" of this so-called "study". Am sure it will follow in the near future.
Aasa
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forbalance
9 Posts |
Posted - 01/28/2009 : 11:13:07
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| What the study proves, John, is that there is no relationship between the dose of thiomersal and neurodevelopment disorders; it's also worth pointing out that one only case of autism was diagnosed in the entire study! For anyone supporting the thiomersal-autism theory, this study should surely make them pause for thought. |
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John Stone
United Kingdom
1254 Posts |
Posted - 01/28/2009 : 12:10:44
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Forbalance
You obviously can't read. In favour of this study is that it is actually written in plain English.
Tozzi, himself, concedes that exposure is not comparable to the US, they didn't do Hep B at birth, sick and low weight babies were pre-excluded by the earlier trial and there was a >30% drop out rate for the tests. Most importantly, as Tozzi also concedes, parents with disabled children might have been less likely to volunteer their children, and (I don't think this is speculation) the more disabled they were the less likely they would be to be volunteered (most ASD children will not get near it - even if they had the conceptual skill to understand the tests, you would not expose them to the stress). The "limitations" are not marginal but actually offer a complete explanation of why there are almost no cases.
But to talk about "proof" is also in relation to this kind of study scientifically illiterate. All they are saying is their findings corroborate other negative findings, but it is a classic example of a study designed to detect nothing. It is frankly a joke: after ten years of time wasting the emperor has no clothes.
quote:
[i]Originally posted by forbalance[/i]
[br]What the study proves, John, is that there is no relationship between the dose of thiomersal and neurodevelopment disorders; it's also worth pointing out that one only case of autism was diagnosed in the entire study! For anyone supporting the thiomersal-autism theory, this study should surely make them pause for thought.
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Edited by - John Stone on 01/28/2009 23:57:03 |
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John Stone
United Kingdom
1254 Posts |
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Govna
43 Posts |
Posted - 01/29/2009 : 02:52:03
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Is anyone able to post a link to a similar discussion of the oft quoted Danish study on the vaccine-autism link?
I still have a lot of catching up to do on this particular topic.
Thanks. |
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Aasa
Canada
731 Posts |
Posted - 01/29/2009 : 04:42:21
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If you're looking for a link to the "oft-quoted" Danish study, and you are asking US, go do your homework elsewhere, and return when you have something to contribute, ye lazy sloth~!!
I don't usually get nasty with posters, but lately the lay of the land seems to have changed somewhat!!
Aasa
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John Stone
United Kingdom
1254 Posts |
Posted - 01/29/2009 : 07:19:01
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Govna
I can't imagine why Aasa was so unhelpful:
http://www.jpands.org/vol9no3/goldman.pdf
http://www.jpands.org/vol9no3/stott.pdf
but bear in mind that they are also corroborated by by the Cochrane review of MMR 2005:
"The interpretation of the study by Madsen was made difficult by the unequal length of follow up for younger cohort members as well as the use of the date of diagnosis rather than onset of symptoms of autism".
What they don't tell you openly was that the younger cohort members were the MMR vaccinated group, thus there was under-ascertainment for autism diagnosis as against controls.
http://mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD004407/frame.html
quote:
[i]Originally posted by Govna[/i]
[br]Is anyone able to post a link to a similar discussion of the oft quoted Danish study on the vaccine-autism link?
I still have a lot of catching up to do on this particular topic.
Thanks.
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forbalance
9 Posts |
Posted - 01/29/2009 : 08:03:18
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"Tozzi, himself, concedes that exposure is not comparable to the US, they didn't do Hep B at birth, sick and low weight babies were pre-excluded by the earlier trial and there was a >30% drop out rate for the tests."
Regardless, you have to accept the fact that you should still see a dose response curve with the differing levels of thiomersal injected.
"Most importantly, as Tozzi also concedes, parents with disabled children might have been less likely to volunteer their children, and (I don't think this is speculation) the more disabled they were the less likely they would be to be volunteered (most ASD children will not get near it - even if they had the conceptual skill to understand the tests, you would not expose them to the stress). The "limitations" are not marginal but actually offer a complete explanation of why there are almost no cases."
Might, maybe, perhaps. Either way, the study is a hefty blow to anyone claiming thiomersal has any hand in autism incidence. |
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john
United Kingdom
591 Posts |
Posted - 01/29/2009 : 08:22:31
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Did someone mention the Danish study---you can see it shredded http://whale.to/a/danish.html
another one for the shredder I see.
this bunch of sheisters don't give up easily
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John Stone
United Kingdom
1254 Posts |
Posted - 01/29/2009 : 08:58:43
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I could not put it better than the poster Doybia in the Robert Kennedy/David Kirby blog n Huffington Post:
"The best way to un-confuse these parents would be for the CDC to actually do a study of the sick children and figure out what happened. Instead of studying healthy kids in Italy they could study sick kids in the U.S. What a concept!"
http://www.huffingtonpost.com/robert-f-kennedy-jr-and-david-kirby/autism-vaccines-and-the-c_b_161395.html
I can't see why you would expect to see a curve at all when all the confounders have been taken into account - you surgically remove all the difficult cases and then you expect to see an effect. Only in the world of pharma CDC doublethink, and Bad Science trolls.
quote:
[i]Originally posted by forbalance[/i]
[br]"Tozzi, himself, concedes that exposure is not comparable to the US, they didn't do Hep B at birth, sick and low weight babies were pre-excluded by the earlier trial and there was a >30% drop out rate for the tests."
Regardless, you have to accept the fact that you should still see a dose response curve with the differing levels of thiomersal injected.
"Most importantly, as Tozzi also concedes, parents with disabled children might have been less likely to volunteer their children, and (I don't think this is speculation) the more disabled they were the less likely they would be to be volunteered (most ASD children will not get near it - even if they had the conceptual skill to understand the tests, you would not expose them to the stress). The "limitations" are not marginal but actually offer a complete explanation of why there are almost no cases."
Might, maybe, perhaps. Either way, the study is a hefty blow to anyone claiming thiomersal has any hand in autism incidence.
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New PEDIATRICS Thimerosal Study
