Cochrane Review: 'Exercise therapy for chronic fatigue syndrome', Larun et al. - New version October 2019 and new date December 2024

Tom Kindlon said:
They continue to classify the PACE Trial as having a low risk of bias in terms of selective reporting which is hard to accept.

This is the comment I made previously:




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I don't know about the old review but the new review specifies the following selection criteria:
We included randomised controlled trials (RCTs) about adults with a primary diagnosis of CFS, from all diagnostic criteria, who were able to participate in exercise therapy.
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PACE was not a RCT. It also plainly concluded no difference in outcome between treatment arms. As the biggest piece of evidence, its own conclusions do not match the review's conclusions.

It seems the material is locked for now so I can't check the other trials but from Vink's review most of the other trials were not controlled as well.

Not the first time I have seen this, using the RCT label then talking only of randomized trials. So it seems to be a new thing, I guess, that RCT also applies to randomized trials. Drop a word here. Add a word there. Change another word's meaning. Ridiculous.
 
Kalliope said:
#MEAction:
Our added points:
1. The review only looks at Randomised Control Trials (RCTs) and doesn't account for patient surveys that show the high rates of deterioration following exercise therapy for ME.
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#MEAction are right that the review authors still claim they "included eight RCTs with data from 1518 participants."

Yet the biggest trial, the PACE trial, wasn't a Randomised Controlled Trial, and even the PIs called it only a "Randomised Trial".
Didn't ceck the other trials.

Edited to add: @rvallee beat me to it.
 
Esther12 said:
Where did you see that? When I ctrl+f it doesn't come up.
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I went to the pdf version and selected the full version. Characteristics of the studies starts at page 44. Pace starts on page 55.

They go through each trial and assess the risks. They don't discuss issues with subjective outcomes with the PACE risks and also give a low risk for "complete outcome data(attrition bias) All outcomes " Low risk "None found"

Although I seem to remember a quite high GET drop out rate I haven't checked

https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD003200.pub8/epdf/full
 
I'll add: I'm not impressed by no conflicts declared from the authors. Laughable. Either Cochrane's entire process is irreparably broken, or it allows arbitrary exemptions that make having a process irrelevant.

Then again, the protocol deviation in PACE is "addressed" by stating it was noted in private steering notes and approved. Approving of a conflict of interest and recording protocol changes does not excuse either, it merely describes what happened, and even at that very reluctantly.

The massive conflicts of interest from PACE authors were not declared either, so this is second degree conflict laundering. What a mess. The promise of a new review in 2020 with this in place is a mockery of clinical evidence and the scientific method.
 
The main thing that strikes me about the differences in this version is the number of times they state "We are uncertain..." (lots and lots).

In the 2017 version, the only time "uncertainty" is mentioned is here:
GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.
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The "interesting" part for me was the substantial change to the Background section of the abstract. I'm not sure it helps though, because it gives the impression that the review adequately considered some things that it clearly didn't. Compare 2017 with 2019:
2017 Background
Chronic fatigue syndrome (CFS) is characterised by persistent, medically unexplained fatigue, as well as symptoms such as musculoskeletal pain, sleep disturbance, headaches and impaired concentration and short‐term memory. CFS presents as a common, debilitating and serious health problem. Treatment may include physical interventions, such as exercise therapy, which was last reviewed in 2004.

2019 Background
Chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME) is a serious disorder characterised by persistent postexertional fatigue and substantial symptoms related to cognitive, immune and autonomous dysfunction. There is no specific diagnostic test, therefore diagnostic criteria are used to diagnose CFS. The prevalence of CFS varies by type of diagnostic criteria used. Existing treatment strategies primarily aim to relieve symptoms and improve function. One treatment option is exercise therapy.
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To me, this indicates that they equate "persistent, medically unexplained fatigue" with "persistent postexertional fatigue" (whatever that is), that the included studies adequately screened for ME (when they didn't).

To try to be positive, they have made a big deal of the chasm in evidence between findings at the end of therapy and long-term, where uncertainty abounds, and the uncertainty over the risk of serious side-effects.

I think they've tried, but all it does is show up that they really don't know what they are doing.
 
Haven't read the new review yet, but I'm rather optimistic by this statement from the new editor in Chief:
we acknowledge that the publication of this amended review will not resolve all the ongoing questions about this globally important health topic. We have decided, therefore, that a new approach to the publication of evidence in this area is needed; and, today we are committing to the production of a full update of this Cochrane Review, beginning with a comprehensive review of the protocol, which will be developed in consultation with an independent advisory group that we intend to convene. This group will involve partners from patient-advocacy groups from different parts of the world who will help us to embed a patient-focused, contemporary perspective on the review question, methods and findings.
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This might be more important than what's in the updated review.

It seems like they have decided to start all over again with this review. It's not made explicit but I suspect that this will involve new authors (would be weird otherwise).

So going back to where the Cochrane email correspondence stops. It seems that the new Editor in chief Soares-Weiser decided that Larun et al. should go ahead and publish the updates they had already worked on, but that this doesn't address all the problems and that Cochrane should simply start over.

I personally would have preferred to have the review retracted as it could be misleading therapists and policymakers. I suspect the current option was the preferred compromise from a political perspective. But it's good news that Cochrane accepts that this updated review doesn't address all the issues and that they want a full update of the review, starting with the protocol (I suspect that means that objective outcomes need to be included).
 
Esther12 said:
Not for the contested one, where it seems like Larun got her way: "There is moderate‐certainty evidence that exercise therapy was probably more effective than control ...

And also "1.8 Self‐perceived changes in overall health
There is moderate‐certainty evidence that exercise therapy probably increases the number of people who report at least some degree of improvement in self‐perception of overall health at end of treatment".
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I do not see how an editor could have approved ‘moderate certainty evidence that probably...’ This is meaningless. Moderate certainty cannot then be qualified by probably.

The text appears to be an appalling case of confused English. I had thought that Cochrane’s GRADE system gauged evidence of ‘moderate quality’ not moderate certainty. Moderate quality evidence of probably would make sense but moderate certainty of probably simply indicates that the authors have no understanding of what they are about.

I am in Peru at present but likely will Communicate with Cochrane about this when I am back.

How can we have a published review with a key conclusion making no sense at all?
 
Jonathan Edwards said:
I am in Peru at present but likely will Communicate with Cochrane about this when I am back.

How can we have a published review with a key conclusion making no sense at all?
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From their correspondence, it looks like 'probably' is standard for moderate quality evidence in Cochrane reviews:

"Some practical issues will arise, e.g. which term shall we use to reflect the grading? Usually
“probably” is used for moderate level evidence, while “may” is used for low level. We are willing to
accept “may”."

https://www.s4me.info/threads/cochr...evelopments-2018-19.10030/page-16#post-205744
 
Michiel Tack said:
Haven't read the new review yet, but I'm rather optimistic by this statement from the new editor in Chief:

This might be more important than what's in the updated review.

It seems like they have decided to start all over again with this review. It's not made explicit but I suspect that this will involve new authors (would be weird otherwise).

So going back to where the Cochrane email correspondence stops. It seems that the new Editor in chief Soares-Weiser decided that Larun et al. should go ahead and publish the updates they had already worked on, but that this doesn't address all the problems and that Cochrane should simply start over.

I personally would have preferred to have the review retracted as it could be misleading therapists and policymakers. I suspect the current option was the preferred compromise from a political perspective. But it's good news that Cochrane accepts that this updated review doesn't address all the issues and that they want a full update of the review, starting with the protocol (I suspect that means that objective outcomes need to be included).
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The statement frankly hits most of the notes and is committal. But the publication of this revised version of the review completely undercuts it. It's very hard to reconcile the two other than this future update being more of the same whitewash. Meanwhile the same recommendations stand as far as health professionals are concerned, despite lacking any credible evidence. After a whole year, there is still nothing but confusion and misleading claims. It still reeks of politics and conflicts.
 
Esther12 said:
From their correspondence, it looks like 'probably' is standard for moderate quality evidence in Cochrane reviews:

"Some practical issues will arise, e.g. which term shall we use to reflect the grading? Usually
“probably” is used for moderate level evidence, while “may” is used for low level. We are willing to
accept “may
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I get that probably is what moderate quality is supposed to mean but you cannot use the same probabilistic statement twice in a sentence. It is a bit like a double negative, it should combine to produce something else.

I think there is a Freudian slip at work here. They wanted to say there was moderate quality evidence... But that would be an outright lie. So they side step using the official moderate quality and use moderate certainty and because that would still be a lie they qualify it with probably. So they end up with a sentence that if it means anything means ‘God knows whether’ but which sounds as if it says moderate quality evidence.
 
Michiel Tack said:
Haven't read the new review yet, but I'm rather optimistic by this statement from the new editor in Chief:
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Yet there is no admission of the serious failures with the review. Or apologies for misleading people.


Michiel Tack said:
So going back to where the Cochrane email correspondence stops. It seems that the new Editor in chief Soares-Weiser decided that Larun et al. should go ahead and publish the updates they had already worked on, but that this doesn't address all the problems and that Cochrane should simply start over.
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This basically shows a very weak editorial process and that they will publish things they know to be wrong. In effect they are admitting their brand is not trustworthy.
 
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