Saturday, April 16, 2011

The PACE trial results show that there is no evidence for using CBT and GET in ME/CFS


Parry’s article is an embarrassment and a very good example of the attitude AYME display in regards to those with the disease ME/CFS. Parry has not understood the research paper, the published literature on the disease ME/CFS, or the chronic fatigue that was studied in the PACE trial.

I’m sure in the coming months we will see several beautifully constructed responses in the Lancet regarding the PACE trial which will explain further the reasons why the trial failed and why Parry has failed to grasp the details of this issue. For now here a few points about her article.

Parry argues that a hypothesis is created and then scientists attempt to knock it down. Yet, the hypothesis tested by the PACE trial was not the one Parry portrays. The trial was not studying the neurological disease ME/CFS, but people with the symptom chronic fatigue in the absence of neurological signs, or “CFS/ME”. As confirmed by one of the authors of the Oxford criteria; “British investigators have put forward an alternative, less strict, operational definition which is essentially chronic…fatigue in the absence of neurological signs, (with) psychiatric symptoms…as common associated features” (Professor Anthony David; BMB 1991:47:4:966‐988)”(1)

Consequently, it is unscientific to then assume, as Parry has done, that ME patients must have been present in the study when this criteria was used in the first round of selection. If the Oxford criteria had been applied correctly there would be no people present with ME.

Therefore, use of the London and Fukuda criteria in subgrouping cannot then have magically have found neurological signs in that cohort. The London criteria are also problematic, but I won’t repeat that issue here, as it is basically irrelevant once the Oxford criteria has selected out those with ME.

They also never tested pacing, but the authors’ creation, which is called “adaptive pacing”. Instead of “listening to your body” and staying within your limits, patients were required to pace to a timetable and set targets. As Professor Hooper has highlighted, the authors of the PACE trial have a very different view of what pacing is and is not. “…the therapists’ Manuals (though not the participants’ Manuals) state that SSMC, CBT and GET may nevertheless all be considered to be forms of pacing.”(1)

It is also a distortion of the truth to suggest that CBT that is offered to cancer patients is comparable to that in the PACE trial. The CBT used in the PACE trial does indeed argue that ME is a psychological disease, perpetuated by incorrect thoughts feelings and emotions.

“CBT was done on the basis of the fear avoidance theory of chronic fatigue syndrome. This theory regards chronic fatigue syndrome as being reversible and that cognitive responses (fear of engaging in activity) and behavioural responses (avoidance of activity) are linked and interact with physiological processes to perpetuate fatigue. The aim of treatment was to change the behavioural and cognitive factors assumed to be responsible for perpetuation of the participant’s symptoms and disability. Therapeutic strategies guided participants to address unhelpful cognitions, including fears about symptoms or activity by testing them in behavioural experiments.“ (PACE trial, page 3)

If a cancer study were created on that basis, then yes the authors would be claiming that cancer was psychological.

Finally, people should now be aware that the results were not clinically significant, and there remains little evidence to support the use of CBT and GET in the management of ME/CFS.

I hope that next time Parry does a modicum of research into the next disease she wishes to involve herself in. As an OBE I would have expected better. What she should have written about is that patients and advocacy groups generally did not wish to see money wasted on a trial of these therapies, but would have preferred investment into biomedical research. An area that at least has a chance to produce effective treatments or a cure for this severe neurological disease.

1) Magical Medicine,

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