Severe ME Day of Understanding and Remembrance: Aug. 8, 2017
Determined to paper the Internet with articles about ME, Jody Smith brings some additional focus to Severe Myalgic Encephalomyelitis Day of Understanding and Remembrance on Aug. 8, 2017 ...
Discuss the article on the Forums.

Chalder Fatigue Questionnaire is a valid & reliable measure of perceived fatigue severity in MS

Discussion in 'Other Health News and Research' started by Dolphin, Jul 8, 2015.

  1. Dolphin

    Dolphin Senior Member

    Messages:
    10,681
    Likes:
    28,210
    Minority interest

    Because of its use in quite a lot of ME/CFS research (including a lot of CBT and GET studies) I thought there might be somebody who was interested in this. I have read it myself as of yet.

    Free full text: https://kclpure.kcl.ac.uk/portal/fi...gue_CFA_final_submitted_MS_JUNE_2015_v4_.docx


     
    Simon, Valentijn and Esther12 like this.
  2. Esther12

    Esther12 Senior Member

    Messages:
    8,449
    Likes:
    28,523
    So how come those with MS who've had CBT report having less fatigue than healthy controls? Seems like that might be a bit dodgy, eh?

    I don't see how these sorts of studies can claims to be assessing 'validity' and 'reliability' unless they totally twist those words to mean something worthless (which does just seem to be acceptable in research of this sort).
     
    Last edited: Jul 8, 2015
    Valentijn, A.B., Kyla and 2 others like this.
  3. daisybell

    daisybell Senior Member

    Messages:
    1,601
    Likes:
    7,362
    New Zealand
    Where do these researchers come from..... King's College London of course. No conflict of interest but a good dose of cronyism.
     
  4. Snow Leopard

    Snow Leopard Hibernating

    Messages:
    4,615
    Likes:
    12,454
    South Australia
    Factor analysis of questionnaires alone? Sigh.

    Sensitivity to change from behavioural interventions is not proof of its validity at all. In fact, if percieved ratings improved, but objective function did not improve, then sensitivity to change from behavioural interventions in the absence of objective changes in functioning proves that it is invalid to use it in this context...
     
    Last edited: Jul 8, 2015
  5. Sean

    Sean Senior Member

    Messages:
    3,257
    Likes:
    17,985
    Worth repeating.
     
    jimells likes this.
  6. Sidereal

    Sidereal Senior Member

    Messages:
    3,097
    Likes:
    17,179
    Wow, they don't even know how to validate a scale. Factor analysis lol
     
    Valentijn likes this.
  7. user9876

    user9876 Senior Member

    Messages:
    2,584
    Likes:
    18,184
    The questionaire

    I've aways found the wording of this questionnaire confusing in that I've never been sure if it is trying to measure change in fatigue or fatigue levels in general. There answer catagories are in the form of 'less than normal'; 'no more than usual'; 'more than usual'; 'much more than usual'

    So I believe that a healthy person would normally score 'no more than usual' on most questions. That is in the time period being asked about then its much the same as other (not well defined time periods).

    For people who have been ill for a long time they say compare yourselves to when you were last well. But for people with chronic illness this can be difficult especially for people who have been ill for a long time. So some 'less than normals' could easily slip in especially given most questionaires are measuring state rather than change in state (e.g. the SF36 scale measures what activities you think you can do) so when given within a bank of questionnaires I think more linguistic confusion would occur.

    So I don't find it surprising that people with MS could get better scores than healthy people because language of the questionnaire is so confused.
     
    hamster336, Esther12, Dolphin and 4 others like this.
  8. user9876

    user9876 Senior Member

    Messages:
    2,584
    Likes:
    18,184
    They also talk about it fitting a bi-factor model with mental and physical fatigue being different factors. What I don't understand is how you can expect to convert a two different factors into an interval scale which is assumed in the stats they are doing. Economists do this with something like the EQ5D scale by surveying a population and estimating a utility function that defines how different dimensions should be combined for a given population - but I think these are largely independant dimensions.

    With the CFQ they have a a number of questions on physical fatigue, a different number of mental fatigue which are clearly correlated to a degree but not completely correlated. They then just sum these up and the bias in the number of questions weights physical fatigue as more important than mental fatigue.
     
    Esther12 likes this.
  9. Valentijn

    Valentijn Senior Member

    Messages:
    14,281
    Likes:
    45,824
    It also sounds like a further foray into turning MS into a partially psychosomatic disease, and minimizing non-fatigue aspects:
    Somehow I doubt that many patients would agree, if any.
    So they aren't really wiped out from being ill, they just think they are. Cue the psychobabblers!
    Unlike subjective symptoms, subjective questionnaire responses are obviously as real and meaningful as objective ones, if not more so :rolleyes: Well, they are if you're a quack whose turn-ons include baseless theories and research which is designed to support your preordained conclusions.

    They're also using the Hospital Anxiety and Depression Scale on MS patients, which is a fairly good one for creating mood disorders out of thin air in chronic multi-system diseases with a lack of effective treatments. And, of course, concluding that fatigue and anxiety or depression are related based upon it. Though they aren't strongly pushing that angle (yet). My guess is that they'll follow up with another study focused on HADS and BDI responses, using this study to cite as support.
     
    Last edited: Jul 9, 2015
    Kyla, Bob and Cheshire like this.
  10. user9876

    user9876 Senior Member

    Messages:
    2,584
    Likes:
    18,184
    I was being slightly inaccurate here.

    They use two different scoring systems in PACE. but in this paper they are looking at the binomial scoring where they group the better, same categories together and group the more than usual an much more than usual together. So a healthy person should generally score around 0 but the linguistics problems persist about what is more fatigue than normal (for a healthy person it could be they are tired due to a deadlines at work, a particularly busy social life etc...)

    What is interesting about their scoring methods if you were to take 100 people who were distributed over the scale using their 'validated' binomial scoring then distribute them using the continuous scoring the order fatiguedness of the people would change. But in this paper they only cover the binomial but with PACE they had to change this so they could get better results.
     
    Snow Leopard and Valentijn like this.
  11. user9876

    user9876 Senior Member

    Messages:
    2,584
    Likes:
    18,184
    Its interesting to validate a one scale by looking it against another with issues

    http://www.jpsychores.com/article/S0022-3999(12)00093-1/fulltext
     
    Valentijn likes this.
  12. user9876

    user9876 Senior Member

    Messages:
    2,584
    Likes:
    18,184

    Reading a bit more

    What they seem to be claiming is that there is a sufficient underlying factor of fatigue so that variations in mental and physical fatigue are small enough to be ignored. This may be because the scale is very course using a binomial marking scheme but I am still very suspicious particularly when measuring change (i.e. score at t0 as compared to score at t1) which I don't think they analyse.
     
    Snow Leopard and Valentijn like this.
  13. Bob

    Bob

    Messages:
    9,844
    Likes:
    33,947
    England (south coast)
    Any half-informed person with a modicum of common sense can see that the Chalder fatigue scale is a poorly designed and inadequate tool. It looks to me as if it's either been designed by very stupid people or by very clever people with an agenda; During the long course of a chronic illness, a patient will surely begin to be unable to recall precisely what 'healthy-normal' feels like, as 'healthy' becomes a distant memory, and as 'unhealthy' becomes the new 'normal' for them. For myself, for example, I've been ill for ten years, and it's difficult to easily recall those healthy summer days when I had boundless energy and could go for a long swim, followed by a walk, followed by a cycle in the sun etc. The new 'normal' is sitting on a sofa. So, if symptoms stay exactly the same, the Chalder fatigue scale will likely record a gradual improvement in health as the patient adjusts and acclimatises to their new situation, even without any improvement in symptoms, simply because of the inappropriate way the questions are worded. And/or the wording will cause consistent or sporadic confusion to the person answering the question unless the meaning of the questions have been repeatedly explained to them. So it's a perfect scale to use for a useless therapy if you want to demonstrate that the useless therapy is effective. It's such a basic common sense flaw that it shouldn't need a published paper to discredit this stupid scale. Then of course, there's the way the scale is inappropriate in terms of assessing severely affected patients, such that the scale can't record the difference between severe and very severe. This seems to cause bias in the scale such that deterioration can't be recorded in severely affected patients. So only improvements can be recorded in some patients. Again, this seems to be incredibly stupid or incredibly clever, depending on the agenda.
     
    Last edited: Jul 9, 2015
  14. jimells

    jimells Senior Member

    Messages:
    2,001
    Likes:
    6,115
    northern Maine
    Inara and Valentijn like this.

See more popular forum discussions.

Share This Page