Cochrane Review: 'Exercise therapy for chronic fatigue syndrome' 2017, Larun et al. - Recent developments, 2018-19

Esther12 said:
their attempts to use low figures for MCID
Click to expand...
Don't think this the core of the issue to be honest. If a treatment like CBT or GET was crafted a little better as a convincing placebo than it might produce larger improvements in fatigue questionnaires. The lack of an adequate control group and the fact that therapists are not blinded to the intervention are the reason why I think there is no evidence for a clinical effect in these studies, not that they used low MCID's.

But perhaps you agree and simply meant that one has to use every argument to explain the case that these results do not reflect real clinical improvements?
 
Esther12 said:
It seems to really vary. Didn't PACE define MCID as half of a measures standard deviation at baseline? There can be research of really varying quality on this too, with some of it seeming to be designed to get a low MCID. I can't remember the specifics of the released Cochrane correspondence now but it sounded like Larun was trying to use research from other conditions to define MCID for CFS patients - I don't think they said specifically which research they were citing.
Click to expand...

What is "clinically important" is qualitative, it cannot be defined by some arbitrary statistical procedure and most importantly, it needs to be defined by patients, rather than defining it as what is most convenient to researchers.
 
Last edited:
It needs to take cost, time and effort into account. A cheap and simple intervention, like adding some magnesium and salt to your water bottle every day doesn't need to produce as large effects to be worthwhile as a costly and time consuming intervention like two hours of some therapy every week.
 
Michiel Tack said:
Don't think this the core of the issue to be honest. If a treatment like CBT or GET was crafted a little better as a convincing placebo than it might produce larger improvements in fatigue questionnaires. The lack of an adequate control group and the fact that therapists are not blinded to the intervention are the reason why I think there is no evidence for a clinical effect in these studies, not that they used low MCID's.

But perhaps you agree and simply meant that one has to use every argument to explain the case that these results do not reflect real clinical improvements?
Click to expand...

I agree it's not a core issue in itself, but think it could still be important.

It could also be that a well done study, that properly explained to patients the potential problems with bias and nonblinded trials before assessing their attitudes to MCID in different circumstances, could be useful for highlighting other problems with GET research.
 
This is a published letter on clinical useful difference:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(11)60689-2/fulltext

Correspondence| Volume 377, ISSUE 9780, P1831, May 28, 2011
The PACE trial in chronic fatigue syndrome
Published:May 17, 2011DOI:https://doi.org/10.1016/S0140-6736(11)60689-2

In their randomised trial of treatments for patients with chonic fatigue syndrome, Peter White and colleagues (March 5, p 823)1
define a clinically useful difference between the means of the primary outcomes as “0·5 of the SD of these measures at baseline, equating to 2 points for Chalder fatigue questionnaire and 8 points for short form-36”. They cite achieving a mean clinically useful difference in the graded exercise therapy or cognitive behaviour therapy groups, compared with specialist medical care alone, as evidence that these interventions are “moderately effective treatments”.

The source for this definition of clinically useful difference states that such a method has a “fundamental limitation”: “estimates of variability will differ from study to study…if one chooses the between-patient standard deviation, one has to confront its dependence on the heterogeneity of the population under study”.2
In White and colleagues' study, we do not have heterogeneous samples on the Chalder fatigue questionnaire and short-form 36 physical function subscale, since both are used as entry criteria.1

Patients had to have scores of 65 or less on short-form 36 to be eligible for the study.1
However, most, in practice, would probably need to have scores of 30 or more to be able to participate in this clinic-based study. Indeed, only four of 43 participants in a previous trial of graded exercise therapy scored less than 30. 3, 4

Guyatt and colleagues 2 suggest that “an alternative is to choose the standard deviation for a sample of the general population”, which White and colleagues have given as 24.1
An SD of 24 gives a clinically useful difference of 12; both graded exercise therapy and cognitive behaviour therapy fail to reach this threshold. Whether they “moderately improve outcomes”, as claimed,
1 is therefore questionable.

References
  1. 1.
    • White PD
    • Goldsmith KA
    • Johnson AL
    • et al.
    • on behalf of the PACE trial management group
    Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial.
    Lancet. 2011; 377: 823-836
    2.
    • Guyatt GH
    • Osaba D
    • Wu AW
    • et al.
    Methods to explain the clinical significance of health status measures.
    Mayo Clinic Proc. 2002; 77: 371-383
  3. 3.
    • Fulcher KY
    Physiological and psychological responses of patients with chronic fatigue syndrome to regular physical activity. Loughborough University of Technology, Loughborough; 1997
    http://hdl.handle.net/2134/6777
    (accessed March 4, 2011).
  4. 4.
    • Fulcher KY
    • White PD
    Randomised controlled trial of graded exercise in patients with the chronic fatigue syndrome.
    BMJ. 1997; 314: 1647-1652
Click to expand...
 



"The Bill Silverman Prize
Purpose
Please note that this Prize is not for the preparation of a Cochrane Review; rather, it is for a published paper which demonstrates originality and critical thinking, either in evaluating any aspect of the preparation, maintenance or dissemination of Cochrane Reviews or about the work of Cochrane more generally. It should be of high quality, have been accompanied by constructive suggestions on how the relevant aspects of Cochrane’s work could be improved; and have had, or is likely to have, a positive impact on the scientific quality, relevance and use of Cochrane Reviews.

Eligibility
Peer-reviewed papers that fulfil the criteria described above under ‘Purpose’, and were published in the twelve-month period 1 April 2018 to 31 March 2019 are eligible for nomination in 2019.
"

pity didn't find out about this earlier (nominations close 2nd Aug).
 
Sly Saint said:



"The Bill Silverman Prize
Purpose
Please note that this Prize is not for the preparation of a Cochrane Review; rather, it is for a published paper which demonstrates originality and critical thinking, either in evaluating any aspect of the preparation, maintenance or dissemination of Cochrane Reviews or about the work of Cochrane more generally. It should be of high quality, have been accompanied by constructive suggestions on how the relevant aspects of Cochrane’s work could be improved; and have had, or is likely to have, a positive impact on the scientific quality, relevance and use of Cochrane Reviews.

Eligibility
Peer-reviewed papers that fulfil the criteria described above under ‘Purpose’, and were published in the twelve-month period 1 April 2018 to 31 March 2019 are eligible for nomination in 2019.
"

pity didn't find out about this earlier (nominations close 2nd Aug).
Click to expand...
Mark Vink and his papers (co-written by a relative (I presume) whose name escapes me) might be suitable??
 
Dolphin said:
Mark Vink and his papers (co-written by a relative (I presume) whose name escapes me) might be suitable??
Click to expand...
Just saw this. Wonderful idea. I've tried to nominate him with this short text:

"Mark Vink wrote two detailed critiques on Cochrane's reviews on CBT and exercise therapy for ME/CFS. His analysis helped Cochrane to adjust and update the review on exercise therapy for ME/CFS. Vinks efforts are quite exceptional given how sick he is due to ME/CFS. In his papers he thanks his parents for writing out his speech memo's as he is too ill to write."
 
You must log in or register to reply here.
Back
Top Bottom