Sunday, 9 June 2013

Month of birth effect is it just nonsense?

 #MSResearch Is it jst tosh

Epub: Fiddes et al. Confounding underlies the apparent 'month of birth' effect in multiple sclerosis. Ann Neurol. 2013 Jun 6.

OBJECTIVE: Several groups have reported apparent association between month of birth and multiple sclerosis. We sought to test the extent to which such studies might be confounded by extraneous variables such as year and place of birth.

METHODS: Using national birth statistics from two continents, we assessed the evidence for seasonal variations in birth rate and tested the extent to which these are subject to regional and temporal variation. We then established the age and regional origin distribution for a typical multiple sclerosis case collection and determined the false positive rate expected when comparing such a collection with birth rates estimated by averaging population specific national statistics.


RESULTS: We confirm that seasonality in birth rate is ubiquitous and subject to highly significant regional and temporal variations. In the context of this variation we show that birth rates observed in typical case collections are highly likely to deviate significantly from those obtained by the simple un-weighted averaging of national statistics. The significant correlations between birth rates and both place (latitude) and time (year of birth) that characterise the general population, indicate that the apparent seasonal patterns for month of birth suggested to be specific for multiple sclerosis (increased in the spring and reduced in the winter) are expected by chance alone.


INTERPRETATION: In the absence of adequate control for confounding factors, such as year and place of birth, our analyses indicate that the previous claims for association of multiple sclerosis with month of birth are probably false positives.


Round 2
Compston-Sawcer vs. Ebers-Ramagopalan

Now that Gorgeous George (Prof Ebers) from Oxford has been put out to grass,  to retire and go farming in Canada, it seems that his Arch rivals-Prof C from Cambridge and the Terrier (I didn't make this one up) are doing their best to undo what Prof E has spent his life doing.

So this report says that the Month of Birth effect is all mushroom food and puts the boot into the Vitamin D hypothesis, which used month of birth effect as part of its justification. 

This comes hot on the heels of Cambridge studies questioning Oxford studies whether vitamin D responsive elements are genetics risk factors. 

Wonder if there will be counter claims that some of the genome studies are just mushroom food also....What do we believe now? Why take so long to counter the original findings? Are their assumptions valid?

Controversy is the Spice of Academia. We need an expert to  discuss this! 

Will Prof E come out of the woodwork for a slanging match? 

Prof G can think about this one whilst in Barcelona at the ENS, I'm not going to pretend I understand the stats.

4 comments:

  1. Statistics is a flimsy foundation for theories of MS. This is probably the future of the EBV hypothesis too, where the main argument is also statistical.

    Go back to the basics and study the lesions, folks.

    ReplyDelete
    Replies

    1. Rich MurraySunday, June 09, 2013 10:19:00 pm
      Yes, Vasilis Vasilopoulos --

      but then I deleted the post because I am fed up with the constant spam.

      If there is something useful to be said then it could be said but the laboured posts on a load of old tosh has got so irritating. I am trying to stop you suffering this constant barage of tosh.

      Should I be pricking hedgehog with flags now, yes I should but at some stage you just have to say your mind. I am biting my lip. I am now reporting this spam. I suggest any recipient do the same.

      A sad state of affairs...... maybe we should have a spam a day and do the same

      Delete
    2. Statistics are the basis for most work in science, if it is isn't staisitically different, it isn't different (Ok we can discuss type iI and II errors-acceptsomething when wrong or reject something that right), if it is statisticslly different is it bilogically meaningful:-)

      Delete
  2. I have always thought that month of birth was an odd choice, why month of birth but not month of conception, or the effect of all the months in between. Also anyone born when vitamin d levels are low was conceived when they were high. As well do not all those vitamin d winters between birth and the arrival of symptoms have an effect.

    However, the biochemists have shown that vitamin d is important to gene function and immunity and influences many autoimmune diseases and real diseases like Hep B. The other strong indicator of an effect from sun light is the difference in MS rate in Australia from North to South and that is observable without statistical manipulation.

    ReplyDelete

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