S4ME: Submission to the public review on common data elements for ME/CFS: Problems with the Chalder Fatigue Questionnaire

Graham said:
I wouldn't be bothered by my "fatigue" if it didn't have measurable consequences.
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But what is causing what? Your fatigue is most likely the caused by the physical condition that also limits you physically. I doubt it is the fatigue causing you to be physically limited, but the physical condition itself. Surely it is the BSP people who argue that fatigue is what prevents some people doing all they physically can?

If fatigue were the limiting factor, not physical condition, then if chased by a bull the odds are a person would still sprint pretty well anyway.

But with the physical condition being the limiting factor, they would far better not get in the bull's way in the first place.
 
I think my postings display both intelligence and fatigue - an excess of one and a lack of the other. I wish I could think clearly enough to work out which way round that is.

All I really meant was that, even if I accept the psychiatrists' concepts, decreasing my fatigue would surely be demonstrated in my subsequent physical performance. If not, if it was merely that we felt better but still couldn't do anything, that's hardly an effective treatment.
 
Graham said:
All I really meant was that, even if I accept the psychiatrists' concepts, decreasing my fatigue would surely be demonstrated in my subsequent physical performance. If not, if it was merely that we felt better but still couldn't do anything, that's hardly an effective treatment.
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Absolutely.
Graham said:
I think my postings display both intelligence and fatigue - an excess of one and a lack of the other. I wish I could think clearly enough to work out which way round that is.
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Your intelligence is always a boost to our advocacy Graham :).
 
Fatigue is part of the behavioural control system in the brain. It's a signal to limit activity and increase rest. Many other factors, such as motivation can counteract the behavioural effects of fatigue (if you're highly motivated, you'll persist in a fatiguing activity for longer).

Studies like PACE seem to demonstrate that manipulating some of the variables involved in this behavioural control system make no meaningful difference to the degree of disability (as one look at long term and objective measures of disability shows). I think the kind of CBT, and LP, are best viewed as motivation technique which has its place in certain situations but don't treat the underlying problem in ME/CFS. Manipulating this behavioural control system is probably even harmful because the low level of activity is an adaptation to the illness (see PEM, whose existence has been repeatedly and objectively demonstrated).
 
strategist said:
Fatigue is part of the behavioural control system in the brain. It's a signal to limit activity and increase rest. Many other factors, such as motivation can counteract the behavioural effects of fatigue (if you're highly motivated, you'll persist in a fatiguing activity for longer).
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Yes. The BPS interventions are based on the assumption that the control system is faulty, and is thereby preventing people achieving a level of activity they are actually capable of, including that needed to break through any presumed deconditioning.

Making that assumption for people where their control system is actually in good working order, and is validly limiting activity to not trigger further physical harm, is downright dangerous and irresponsible. Like telling someone to lift a weight far exceeding their physical capability, but first administering pain killers.
 
Barry said:
Also, over the past few weeks it has finally clicked with me why the name Chronic Fatigue Syndrome is such a misnomer and such a disaster; I've been reading it for ages but not really understood. The "fatigue" word hands ME patients to psychiatrists on a plate! Fatigue can only ever be measured subjectively, which is the psychiatrists' natural habitat. And because fatigue is also associated with genuine mental conditions, I think the BSP psychiatrists think they own any condition with the word 'fatigue' in its name. And their scientific skills seem inversely proportional to their arrogance.
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Nicely said, @Barry!
 
I found this questionnaire weird when I saw it the first time. (It is used in Berlin amongst others.) And this question, if you have problems with starting things, puzzled me exceedingly. I left it open. I discussed it with the doctor, and she explained it is not meant as lack of motivation (like in depression), but if - on an "energy" basis - I have problems to get new things accomplished, which I have to agree to, at least in part. But it's not lack of motivation, it's lack of "energy" - or whatever to call it, don't know. And it's always thinking about whether it might cause PEM and if it needs proper preparation to avoid it.

I don't recall the questionnaire asked whether your fatigue etc. disables you, but if you feel it more than usual. (I was told that means pre-illness level.) And to be honest, I have problems concentrating, finding words, and I feel more tired than before (but tiredness doesn't disable me) and so on...Don't the others?
It's definitely not all-imbracing, though.

I get the feeling I might have misunderstood it completely. Makes me uneasy somehow...

Blah -
Thanks for all your effort! I am so excited about what will happen.
 
petrichor said:
I didn't say that my activity is primarily limited by my primary feelings of fatigue, but that doesn't meen that I don't experience feelings of fatigue, and the things this questionnaire covers.

That's a very big extrapolation to jump to, and it's completely untrue. I assure you, I know my symptoms far better than you know them.
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Sorry to offend you, @petrichor.

As a new member, I thought you might be genuinely interested in knowing that other people's experience is a little different. I was in no way saying your symptoms were not awful or debilitating, not at all.
 
Andy said:
Huh? Woolie isn't saying that you don't experience fatigue, why are you claiming that she is? And in your post you say

which IS different to what most patients describe. Reading your post, it does come across as you saying that it's fatigue limiting your activities, not the concern of triggering PEM, so I can understand why Woolie says what she does. So no big extrapolation to jump to, your post leads us to believe it to be the case. Now with your later post you explain that isn't the case, which helps us understand your situation - and of course nobody here is claiming to know your symptoms better than you, all we can go on is the information that you give us in your posts.
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Woolie said:
Sorry to offend you, @petrichor.

As a new member, I thought you might be genuinely interested in knowing that other people's experience is a little different. I was in no way saying your symptoms were not awful or debilitating, not at all.
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Thank you, I'm glad that you didn't mean that response in that way. I assure you, my primary limiting factor is PEM, and I meet the IOM diagnostic criteria perfectly.

I don't think that anything in my post particularly implied that wasn't the case, I was just talking about fatigue in a fairly general sense. It doesn't matter though, just a misunderstanding.
 
Woolie said:
Good find, @arewenearlythereyet. Although if we want to use this scale in MECFS samples, it needs to be validated on that population. Controls just does not cut it.
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Absolutely ..once validated the test should stand up on its own, but I was suggesting a control group to validate it before it is used widely. this to validate the test method itself to see how precise any proposed scale is. Hence if validation shows that healthy people come out scoring high and not much different to your target group...you know the questionnaire/scale needs redesigning.

i suspect that the Chalder scale has had no proving done on it since it looks like it's been crafted fairly crudely, and seems to be missing an awful lot of basic best practice. I doubt that there was any validation in terms of elliminating bias from the scales used or the rather dubious wording of the questions.
 
arewenearlythereyet said:
Using sliding scales instead of fixed scales (e.g rating scales with even number end point (e.g 1-10) have been shown to suffer from end point avoidance so 1-9 is better for this ...sliding scales are even better)
1). Testing and analysis of wording used in the question phrasing to show that wording had been considered to avoid questionnaire bias ( there seems to be a lot of leading questions used rather than neutral questions)
2). Using open questions rather than specific questions is never a good thing for quantitative data collection
3). Repeating the same question in different guises also causes bias from questionnaire fatigue
4). The screened target has been tested with the questionnaire vs a control group to give an indication of the effectiveness of the scale used.
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Good points. I think there is a real problem in the medical world in terms of how questionnaires are structured. They don't seem to understand the basic principles that are well known in say the marketing literature. Too often they label scales as 'likert' scales because they use likert item like scoring schemes but even here they forget that the scoring schemes need to be able to cover the full range of possible outputs.

I'm not sure about your point 4, If the scale is intended to act with a threshold to help discriminate a group then I would agree although tests on different groups would be needed. But if the scale is intended to be a linear proxy that measures fatigue accurately then more needs to be done to validate that scores are equi-distant and have a meaningful representation in reality. This is how the scale is being used in a trial where it is basically being used to measure change.

Having two scoring systems where with one a fatigue reduction is shown and the other a fatigue increase demonstrates there is something very dodgy with at least one of the scoring systems.
 
Adrian said:
Good points. I think there is a real problem in the medical world in terms of how questionnaires are structured. They don't seem to understand the basic principles that are well known in say the marketing literature. Too often they label scales as 'likert' scales because they use likert item like scoring schemes but even here they forget that the scoring schemes need to be able to cover the full range of possible outputs.

I'm not sure about your point 4, If the scale is intended to act with a threshold to help discriminate a group then I would agree although tests on different groups would be needed. But if the scale is intended to be a linear proxy that measures fatigue accurately then more needs to be done to validate that scores are equi-distant and have a meaningful representation in reality. This is how the scale is being used in a trial where it is basically being used to measure change.

Having two scoring systems where with one a fatigue reduction is shown and the other a fatigue increase demonstrates there is something very dodgy with at least one of the scoring systems.
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I also wonder if there is an issue with presumtions of linearity? (I don't know if it's an issue, but worth asking). When the results are analysed, do the interpretations presume a linear scale? And if so, is it really linear?
 
Barry said:
I also wonder if there is an issue with presumtions of linearity? (I don't know if it's an issue, but worth asking). When the results are analysed, do the interpretations presume a linear scale? And if so, is it really linear?
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The stats (quoting mean and sd) assume that the scale is linear otherwise if it is ordered (ordinal scale) then the median and MAD can be used. If not (as I think is the case for the CFQ) only the mode should be given.

When comparing improvements you cannot do that if an improvement of 1 point in real fatigue is measured as an improvement of 3 points on your proxy scale (the CFQ) when at position X but only 1 point if at position Y. So the proxy scale needs to map well onto the actual fatigue values (if such a thing really exists!). Problems such as possible answer set for the scale not equally representing all the set of values but say cutting off at bad (and not representing very bad or changes from that) have an obvious effect.

But so do issues about question content. If three questions are very related then a fairly small real change may lead to large amounts of reported change if the person is on the scale at a point where the answer to those questions will flip. Hence it is very important to understand how each question fits onto a real measure of fatigue. I would argue that to be a proper scale these questions would been to be ordered and the order would be valid for most people.

There is a further issue in terms of ordering which is if mental and physical fatigue can vary independently (or sometimes do) then the CFQ is actually the sum of at least two different basic things to measure with different weightings given different numbers of questions for each. So a 1 point improvement on a mental fatigue and a 1 point worsening on physical fatigue will lead to a (potential) worsening of the CFQ but the other way around an improvement. This is not based on a 'fatigue utility' i.e. looking at how people value the different components but is arbitary in the make up of questions. It also implies non-monotonic orderings.
 
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