calvin, i’m not sure i can be bothered with another thread being hijacked with people feeling the need to explain to you about your misunderstandings in such painstaking detail.

youre very welcome indeed in the forums but its nice to have slightly more interesting and focused discussions on these entries. you’ve had a good run taking one over.

is that okay with you?

badscience.net/forum and people can choose if they want to engage with it/you.

But now I’ve proved that you fundamentally misunderstood the Honda paper I think we’d better call this thread a day.

Bye.

So essentially you are claiming that subsequent to the withdrawal of MMR rates of autism actually increased. In this study consistent diagnostic criteria were adhered to, so therefore, your claim that there was a notable rise in the number of cases of autism after the withdrawal of MMR essentially capsizes your previous rubric that evolving diagnostics is responsible for the apparent rise in cases of autism.

If a consistent diagnostic analysis shows that withdrawal of the MMR presages a rise in case of autism, Dr Honda has proved that MMR helps to prevent autism. Is this acclaim that the good doctor would care to standby?

To anyone not paying attention (i.e. calvin) – what I’m saying is that this objection by calvin only applies if they are looking at annual autism rates – however, they are not doing this, they are looking at the 7-year autism rates by year of birth.

MMR vaccination stopped in 1993, so cohorts born in 1992, 1993, 1994, 1995, and 1996 didn’t receive MMR, and vaccination rates declined from 70% in 1988, and each cohort was followed up for 7 years to see if they developed autism in that time.

If you look at the figure I put up above you can see that they report the cumulative rates of autism over 7 years by year of birth – so none of your complaints about it taking time for cessation of MMR to have an effect make any sense – children born in each year were followed up for seven years.

The rate of autism went up and MMR vaccination rate went down. And your only objection to the paper shows you don’t understand it.

What difference does that make? This simply extends the time allowed for diagnosis. This” extra time” is granted equally to the pre-MMR patients and the post MMR patients. The effects of five years of MMR extended seven years into the future was being compared to the effects of three years of single jabs extended seven years into the future, that would seem to weaken the credibility of the study, not strengthen it.

http://pyjamasinbananas.blogspot.com/2007/07/what-happens-to-autism-if-we-stop-mmr.html

Note that they followed up to 7 years, it is just that the last birth cohort was in 1996. Also MMR vaccination rates were rapidly falling in the period before they were stopped altogether. They also note that in Japan MMR was given at 1 year.

autistic disorder – 37 months
PDD-NOS – 45 months
Asperger’s disorder – 86 months

Theoretically a definitive diagnosis of any ASD ought to be possible prior to 36 months because the symptoms needed for diagnosis are supposed to be evident by that time.

What is the source of your figures for age of diagnosis?

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=15877763&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

“This study examined cumulative incidence of ASD up to age seven for children born from 1988 to 1996…The MMR vaccination rate in the city of Yokohama declined significantly in the birth cohorts of years 1988 through 1992, and not a single vaccination was administered in 1993 or thereafter. In contrast, cumulative incidence of ASD up to age seven increased significantly in the birth cohorts of years 1988 through 1996 and most notably rose dramatically beginning with the birth cohort of 1993.”

“Dr. Honda’s work is said to be the first investigation of a possible MMR link to autism in an environment where the MMR vaccine was not being used. Together with colleagues Dr. Shimizu and Dr. Rutter, Dr. Honda examined records of 31,426 children born in a single Yokohama district between 1988 and 1996. The team discovered that the rate of autism, which has been increasing in recent years, continued to increase among the children in the study group even after the MMR vaccine was withdrawn from use”

Japan stopped using the MMR in 1993. Autism is not generally definitively diagnosed any earlier than four years old, in America a formal ASD diagnosis is more generally made at 61 months. This would mean that it would take at least three years for the cessation of the MMR to have a statistical impact and at least three years for the impact of the new regimen to become apparent.

Japan stopped using MMR in 1993, given an innoculation age of about one and a half and a diagnosis age of around four and a half, it is clear that the effects of this would not actually become apparent until after 1996, which is the cut off point for Dr Honda’s study. It is also true that it would take around three years until the the previous MMR inoculation programme could reasonably be considered not to be a relevant causative factor.

It seems to me that Dr Honda has precisely chosen to narrow the scope of his study to a timesacle within which the effects of the new single jab innoculation programme would not be appparent and within which the effects of the previous MMR innoculation programme would stll be a major influence.

Even if you quibble about the precise age of administration and diagnosis, it is still clear that the large degree of overlapping of influence sinks the validity of this study, a study that is touted as a major blow to the credibility Wakefield hypothesis seems to be nothing more than crude statistical chicanery to me.

The reason that autism rates are finally catching up with Wing and Gillberg is because the diagnostic criteria have changed to reflect our growing understanding of autism.

I wrote a long blog about the epidemiology of autism in response to Lathe’s really bad book on the subject. Check it out, Calvin and note three things.

1. MMR was introduced into the USA a decade before its introduction to the Uk and had no effect on reported rates of autism.
2. The 91 in 10000 figure is based on research that preceded the introduction of MMR into the UK.
3. The supporters of the MMR hypothesis usually argue the number of affected children is so small that they would not be statistically detectable in epidemiological studies. So how can the “increase” in autism statistics be down to the statistically undetectable MMR? effect

http://pyjamasinbananas.blogspot.com/2007/07/changing-diagnosis-of-autism.html

showing a rather striking temporal relationship between mental retardation diagnoses and autism prevalence.

I’m interested calvin, how you reconcile your claim that increasing autism incidence is progressive and continuous (not something you have presented evidence for) with your explanation that it is due to MMR since, as the Chakrabarti & Fombonne study above suggests, the MMR rate peaked in the years it as introduced, and then slightly declined, not something that the autism figures have reproduced, while you’d predict a plateau – the very thing you are claiming that the changing diagnostic practice argument claims (but it doesn’t as I’ve shown) and is thus undermined by.

“It should be remembered that the concept of pervasive developmental disorders and of a spectrum of autistic disorders is relatively new. Previous epidemiological investigations mostly concentrated on autistic disorder, often on a much narrower definition of autistic disorder than that currently employed. In prior surveys, a relatively high number of children described with different labels (i.e., atypical autism, autistic features, etc.) (4) did not meet the full criteria for autism and were usually not incorporated in prevalence calculations. Therefore, a direct comparison of current rates of pervasive developmental disorders with prevalence estimates from past surveys should not be performed, as they relate to different case definitions…One of the goals of this repeat survey was to apply rigorously the same methods to identify in the same population children with pervasive developmental disorders born in consecutive birth cohorts. If the prevalence figure for our new sample had increased from that in the previous study, that might have pointed toward an increase in the incidence of pervasive developmental disorders, consistent with the various claims of an “epidemic of autism” (4, 5). We did not find such an increase, and there was no statistical difference between the two prevalence rates, not even a trend in that direction. It can therefore be safely concluded that, in this area and for children born over the period 1992 through 1998, there was no evidence of a secular change in the incidence of pervasive developmental disorders. In investigations where upward trends in prevalence rates were observed, changes over time in diagnostic criteria and detection of autism could not be ruled out as explanatory factors.”

http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=retrieve&db=pubmed&list_uids=12108622&dopt=AbstractPlus

“These data demonstrate a dramatic increase in the
prevalence of full syndrome autism among children
born in California between 1987 and 1994…During
the same time period, a decrease of comparable magnitude was observed in the prevalence of children…with a diagnosis of [mental retardation] of unknown
etiology.”

http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=retrieve&db=pubmed&list_uids=14695031&dopt=AbstractPlus

“In the early 1990s, boys with diagnosed developmental disorders were infrequently diagnosed with autism. In the later 1990s, such boys more often were diagnosed with autism. CONCLUSION: A major cause of the recent large increase in the number of boys diagnosed with autism probably is due to changing diagnostic practices.”

Of course, changing criteria are not the only explanations, there are also arguments that awareness has increased and age of diagnosis has decreased.

By your argument there was no autism before the 1940s because autism hadn’t been invented yet.

As yet we can’t be sure that there is a true rise in autism rates (although there may be). The only association is that MMR has been used in some countries recently-ish, and autism -may- have gone up recently-ish. But further analysis has shon that there is in fact no temporal association with MMR, and this has been shown by many studies (e.g. http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=11222420&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum but many others too)

Studies of birth cohorts in France using the same criteria for autism have not found increased prevalence:

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=9394941&ordinalpos=3&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

And studies of the diagnostic criteria have shown differences between the different instruments:

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17513984&ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=8906453&ordinalpos=22&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed&Cmd=ShowDetailView&TermToSearch=17450055&ordinalpos=4&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum

“Autism has been quite clearly understood for decades, improved diagnostics would make little impact except in the diagnosis of mild to borderline cases.”

You appear to have very little familiarity with psychiatric nosology. Autism is not just something binary that people either have or do not have, with some special test to confirm or refute it – it is diagnosed using criteria which are agreed by a committee of doctors, and are thus somehat arbitrary, and which can change with time as the diagnostic criteria are altered and refined.

“There has been a rise in Autism, there is a temporal association with MMR, your refutation of a correlation is based on unsubstantiated hypothesis about diagnostics. You have a very weak case, which is why you concentrate on attacking Wakefield’s hypothesis.”

Christ all fucking mighty, have you not heard of the many studies into MMR and autism showing that there is not a temporal relationship between MMR and autism in Sweden, the US, or Japan, and that the rise in the UK precedes the introduction of MMR?

This is what I mean, you base your view on no evidence combined with a refusal to seek out any evidence that refutes it!

I believe that the commenter was claiming to be a doctor, in which case I do think that he has a duty to reveal the data that has led him to support his present position.

The argument that the increase in autism is due to improved diagnostics is not supported by proper research. Can you show me a substantial study of historical case histories of mental patients who can now be reasonably considered to have been misdiagnosed autistics? No such study has ever been undertaken.

Autism has been quite clearly understood for decades, improved diagnostics would make little impact except in the diagnosis of mild to borderline cases.

“despite the extensive evidence that there has been no rise of autism associated with the use of MMR”

There has been a rise in Autism, there is a temporal association with MMR, your refutation of a correlation is based on unsubstantiated hypothesis about diagnostics. You have a very weak case, which is why you concentrate on attacking Wakefield’s hypothesis.