Choline on the Brain? A Guide to Choline in Chronic Fatigue Syndrome
http://phoenixrising.me/research-2/the-brain-in-chronic-fatigue-syndrome-mecfs/choline-on-the-brain-a-guide-to-choline-in-chronic-fatigue-syndrome-by-cort-johnson-aug-2005
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Williams, White et al: PACE: Heterogeneity in CFS - empirically defined subgroups [...]

Discussion in 'Latest ME/CFS Research' started by mango, Jan 24, 2017.

  1. sarah darwins

    sarah darwins I told you I was ill

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    "We're gonna bin so much you may even get tired of binning"
     
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  2. user9876

    user9876 Senior Member

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    They chose a set of variables and then saw clusters. I would assume an amount of playing with data etc to get the clusters they wanted. Given other papers they have written I would be suspect about any stats they use.

    Even if it were a good methodology, finding clusters in symptoms or other collected data in no way helps suggest mechanism. At best clusters could provides suggestions to look at not conclusive results.
     
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  3. Joh

    Joh Inactivist

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    Not sure, if I understand that right. Does that mean, that the largest subgroup is mentally strong and free of false illness beliefs (even from the authors' viewpoint)? That they have a biomedical illness and CBT would do nothing for them?
     
    Last edited: Jan 25, 2017
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  4. Forbin

    Forbin Senior Member

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    According to the paper It appears to mainly be a problem of statistical power (studies are too small), small effect size and various forms of bias that can creep into study design and analysis.

    http://statweb.stanford.edu/~tibs/sta306bfiles/ioan.pdf
     
    Last edited: Jan 24, 2017
  5. Sean

    Sean Senior Member

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    IIRC, professional clinic opinion is at the bottom of the formal evidence rankings.
     
  6. Barry53

    Barry53 Senior Member

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    Good heavens! How could you possibly suspect them of something so underhand as that! :p;)
     
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  7. AndyPR

    AndyPR Senior Member

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  8. user9876

    user9876 Senior Member

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    Using PCA to reject variables may well remove outlier clusters which represent a pattern for just a few patients. The way the variables explain the overall variance may be low but it may stick out for a few samples.

    What seems strange is they turned continuous variables into binary ones using the median as a threshold. So the PCA is really done on whether some variables are above or below the median which seems strange to me.

    But perhaps the variance in the data set just represents the values they have chosen to collect - rather than anything that is an actual effect.

    The labelling of clusters is probably the most interesting thing as it represents their interpretation of the features in the cluster and hence expose
     
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  9. user9876

    user9876 Senior Member

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    Given their comment

    I think my comment is fair.

    I take the last quote as saying that they interpreted their data with respect to their existing biases.
     
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  10. Sean

    Sean Senior Member

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    Looks like Post-hoc Syndrome is spreading like wildfire through the psych research community.
     
  11. Snow Leopard

    Snow Leopard Hibernating

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    Circular reasoning for the win!

    Also, notice how they're not publishing in an open-access journal?
     
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  12. Snow Leopard

    Snow Leopard Hibernating

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    It is indeed strange to me, but I don't know how common this may be in psychology.

    Have the all the medians for the continuous variables they've used been published in other papers?

    Is this really a valid idea if the data for that variable is normally distributed?

    Should the split be defined a priori so that it is not inherently dependent on the specific dataset (because it means any other data set they analyse could have quite different split values)?
     
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  13. user9876

    user9876 Senior Member

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    I don't think medians have been published. The reason for using the median and not the mean is it is more robust and hence good for differing distributions hence used in a lot on non-parametric stats.

    But PCA works on continuous variables (assuming they mean principle component analysis)
     
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  14. Snow Leopard

    Snow Leopard Hibernating

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    Also,

    I know certain people will certainly be frowning after reading this...

    It's kind of ironic that this study is proving what some people were saying: many of the patients included were not the Typical ME patients we know and love, but rather mildly affected "chronic fatigue" patients with mood/anxiety disorders.
     
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  15. alex3619

    alex3619 Senior Member

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    It was already there it was just hidden due to diagnostic failure.
     
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  16. soti

    soti Senior Member

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    Yes, for LCA if I recall correctly you need to know how many groups you want. Essentially it involves squinting at the data and seeing if, e.g., the solution looks better with 3 or 4 clusters. So it works best in a case where the real solution is much better than the non-solutions.
     
  17. Sidereal

    Sidereal Senior Member

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    I think the PACE dataset is quite interesting in the sense that it demonstrates that CBT is an ineffective treatment even for depression/anxiety-related fatigue given that it looks like only about 11% had actual ME/CFS. I have for a long time criticised clinical psychology for being a pseudoscience pushing bogus psychotherapies. In order to raise their status/income they strenuously oppose the more effective (albeit still largely unsatisfactory) biological treatments for psychiatric conditions, constantly trying to undermine the biological model. In recent years the quackery has really reached fever pitch levels / reductio ad absurdum with their advocacy of useless/harmful nonsense like CBT for psychosis which is a neurodevelopmental brain disease. It's all the more strange seeing fringe medical doctors like White/Sharpe pushing psychosocial quackery. They really should know better.
     
  18. Barry53

    Barry53 Senior Member

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    Of course it is; I was/am wholeheartedly agreeing with you. I think my intended humour must have got "lost in the post".
     
    Last edited: Jan 25, 2017
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  19. Ben H

    Ben H OMF Correspondent

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    I had a good laugh at this, thanks! 10/10 sarcasm :D


    B
     
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  20. K22

    K22

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    They clearly believe those of us who believe are symptoms are physical and exacerbation could mean harm still have faulty illness beliefs. What is any non ME sufferer, say a skeptic dr going to surmise from this paper other than at least some of symptoms aren't physical and that if we say we are too sick to do GET we just have "unhelpful avoidance behaviour". I for one used to have a GP who, I'm sure on the basis of this type narrative, concluded my main issue wasn't over riding disability but was a treatable lack of motivation and unhelpful beliefs about my illness and rehabilitation prospects - que much stress as she tried to get help in to motivate me.
     
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