MMR and statistics and science

16 Oct

Measles Mumps Rubella Timeline

Now that we have a couple of clinical papers refuting the findings of Wakefield, Krigsman, O’Leary et al – and not only refuting them but even showing exactly how they screwed up – I thought a retrospective look at the data concerning the fall in uptake of the MMR vaccine corresponds to the latest data on prevalence for autism in the UK and what it might mean for the MMR theory.

This table shows vaccination uptake rates across England. I’m going to highlight the years 97/98 – 04/05. An eight year period that starts when the original Wakefield paper was released and ends with the latest set of known data from last year. I’ll also be ignoring everything except MMR data.

Year Uptake percentage
2nd birthday in 1997/98 91%
2nd birthday in 1998/99 88%
2nd birthday in 1999/00 88%
2nd birthday in 2000/01 87%
2nd birthday in 2001/02 84%
2nd birthday in 2002/03 82%
2nd birthday in 2003/04 80%
2nd birthday in 2004/05 81%

So we can see that MMR uptake _dropped by a factor of 10%_ in eight years. Thats a pretty sobering stat.

When we look at how many live births there have been between 1998 – 2005 (inc) we see that there have been a total of 4,959,995. Ten percent of _that_ figure means that 496,000 have not (for whatever reason) received the MMR. And if prevalence (as established by Baird et al) really is 1 in 100 then we should expect to get 49,599 diagnosis of autism since 1998 (1% of live birth rate).

But, if MMR proponents are right, then we _should not_ have 49,599.autism diagnosis. We should have 45,036 (49,995 (dx) – 4,959 (10% of dx)).

To put it another way – if MMR uptake has fallen by 10% over the last 8 years, then there should’ve been a corresponding 10% fall in autism diagnosis. Has there been?

Obviously not. Bill Welsh of the Autism Treatment Trust certainly doesn’t think so:

It will come as no surprise to parents throughout Scotland that there has been a “sharp increase in autism” (July 14). The diagnosis of this devastating childhood developmental condition has increased to such an extent since 1990 that many, many families are now affected. It is very worrying that it has taken well over 10 years for the authorities at last to recognise that an autism epidemic has been sweeping the UK.

And lets not forget Chakrabarti and Fombonne who also found a high but stable prevalence of autism in the UK. Both things cannot be true. If MMR causes autism then as MMR uptake has dropped off the rate of autism cannot possibly have remained the same, unless we want to try and find a substitute that not only acts in the exact same way as MMR but also slots exactly into the numerical data, rising as MMR falls. Possible but pretty unlikely.

8 Responses to “MMR and statistics and science”

  1. Joseph October 16, 2006 at 18:18 #

    Not as clear as the evidence against thimerosal, but yeah, if MMR uptake drops, why no impact on autism incidence?

  2. David N. Andrews MEd (Dec 2006) October 16, 2006 at 20:16 #

    Because MMR vaccine doesn’t cause autism, perchance? 🙂

  3. anonimouse October 16, 2006 at 20:23 #

    It’s fascinating that this is never discussed by the anti-vax loons.

  4. Ms. Clark October 16, 2006 at 21:11 #

    Thanks, Kev.

    Now let’s all hope the MMR uptake rises again. This business of Mrs. Dr. Dreamy Wakefield kvetching about the parents needing the separate M M and R is stupid. They only want them separate because her husband scared everyone away from the combo vaccine…. and then there’s all this “horizontal transmission” with kids getting measles from their siblings’ vaccines (through fecal oral transmission?)… except that Wakefield et al weren’t finding measles in the first place, they were finding junk, so if they found “measles” in the siblings using the Wakefield technique, they weren’t finding measles at all. Hmmm.

  5. Brian Deer October 16, 2006 at 21:35 #

    Real afficianados of these things will have seen Dr Edward Yazquack’s regular diatribes, claiming that Wakefield didn’t start the MMR scare in the UK, on account of the fact that immunization rates were falling from 95 onwards, not 98, when the famous Lancet paper was published.
    Fact is, Wakefield had already launched a campaign, in 1995, claiming that measles-containing vaccines caused Crohn’s disease. It got a lot of media attention, although we’re inclined to overlook that all these years later.

    A useful way of tracking what happened is in the UK Department of Health’s data:

    http://briandeer.com/mmr/uptake-stats.htm

  6. clone3g October 17, 2006 at 18:54 #

    It’s weird the way Andy’s wife is jumping to his defense all the while ignoring the central question: Does MMR cause autism and do autistic kids have live measles virus in their guts?

    She’s going on about gut inflammation and how doctors should be looking in to the issue, seeing if gut inflammation is more common in autistic children, etc.

    Has anyone told her that Wakefield’s bad science created an obstacle to good science? If he really wanted to help autistic kids and settle it once and for all he would have shared his samples with other labs including the team who recently failed to find measles DNA in PBMC’s.

  7. anonimouse October 17, 2006 at 19:13 #

    Wakefield wants to help himself to more money. I don’t believe he gives a rat’s ass about children, since he’d recommend leaving them vulnerable to potentially serious diseases for months longer than necessary.

  8. Ms. Clark October 19, 2006 at 22:13 #

    Clone, She’s standing by her man… on a slippery slope… but she’s standing by her man… (yech). I hope she likes life in Texas. I think it’s Venezuela next.

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