1. Patients launch $1.27 million crowdfunding campaign for ME/CFS gut microbiome study.
    Check out the website, Facebook and Twitter. Join in donate and spread the word!
Ergonomics and ME/CFS: Have You Hurt Yourself Without Knowing It?
Having a chronic illness like ME/CFS can make it hard to avoid problems that come from bad ergonomics. Jody Smith has learned some lessons the hard way ...
Discuss the article on the Forums.

The evolution of assessing bias in Cochrane systematic reviews of interventions: celebrating methodo

Discussion in 'Other Health News and Research' started by Esther12, Sep 28, 2013.

  1. Esther12

    Esther12 Senior Member

    Messages:
    5,267
    Likes:
    5,474
    http://www.systematicreviewsjournal.com/content/pdf/2046-4053-2-79.pdf

    I was just reading this paper, and some bits stood out to me as possibly interesting and relevant to CFS, so I thought that I would pull them out.

    Some of the history was interesting, as I'd assumed people were sceptical of the processes of science far further back than this... maybe it took time for anyone involved in science to get around to gathering evidence of these problems?:




    I know nothing about this stuff, so it's all quite interesting:




    Some quite nice summaries of important issues, and possibly worthwhile references:









    Apparently some evidence that assessors of bias can be biased by reputation of institution, researchers, etc:




    They talk about CONSORT being an important move forward, which is something I really don't know enough about.

    I don't know about EQUATOR either, but it sounds of interest:




    [ http://www.equator-network.org/ There is a copy of the CONSORT guidelines their, but it looked like the site might be difficult to browse unless you knew what you were looking for. (Having said that, I've now found a few interesting bits in their 'news' section).]

    A bit on registration:





    A bit OT, but this bit reminded me of Jonathan Edward's reporting that he thought multi-centre RCTs were often less effective as it was harder to keep high standards for patient selection, while here it is argued that this differences is likely to indicate a reduction in bias with multi-centre RCTs:




    Yay, it was only 9 pages long, as it's got 10 pages of references - I feel so free!
    Sean likes this.
  2. Denise

    Denise Senior Member

    Messages:
    185
    Likes:
    246
  3. WillowJ

    WillowJ Senior Member

    Messages:
    3,059
    Likes:
    2,607
    WA, USA
    Either explanation would produce the same effect.

    If inappropriate patients are being recruited because some institutions are being used which don't really understand the nuances of the disease (e.g. they can't tell chronic fatigue from ME or from any other disease which they should have diagnosed instead) or of the treatment requirements (say it was RA but the treatment was expected to help only certain types of RA patients), the same treatment won't help. (could this called bias? and then it would be the same as what Cochrane is saying anyway?)

    Or if a certain institution has a high "provider allegiance" and insufficient controls (e.g. unblinded assessment), it could be a design flaw introducing bias.
    Valentijn and Esther12 like this.
  4. Esther12

    Esther12 Senior Member

    Messages:
    5,267
    Likes:
    5,474
    Yeah. I would have instinctively assumed that the Cochrane interpretation was right had I not earlier read Edward's comment. Which is not to say that the Cochrane interpretation is wrong - it could be that the effect Edward's is frustrated by is a result of his reduced ability to (unintentionally) bias results in multi-centre RCTs.

    It just shows how important it is to keep trying to distance oneself from stories, and remember how little the evidence really shows. There are often a number of different interpretations for particular findings.
  5. WillowJ

    WillowJ Senior Member

    Messages:
    3,059
    Likes:
    2,607
    WA, USA
    I meant to say that if we consider inappropriate patient selection a type of bias (something which skews the results), then it's possible Edwards and Cochrane are saying the same thing. (I edited my post to make this more clear)

    In other words, it's the multi-center design where other centers don't understand either the patients or the treatment or both, which introduces the bias in Edwards' version.

    When things differ, it's not obvious which version is biased. The better result could be biased, or the worse result could be the biased version, depending on what factor is introducing the bias.

    I guess we are saying the same thing!
    Esther12 likes this.
  6. Esther12

    Esther12 Senior Member

    Messages:
    5,267
    Likes:
    5,474
    I could have misremembered this, but I'm pretty sure that they were saying that multicentre is more reliable, and I just only quoted a small section. To some extent, as a reflection of real world outcomes, this is almost certainly the case.

See more popular forum discussions.

Share This Page