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PACE Trial and PACE Trial Protocol

Discussion in 'Latest ME/CFS Research' started by Dolphin, May 12, 2010.

  1. Dolphin

    Dolphin Senior Member

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    Another witness account: CBT: fewer symptoms ... but able for fewer hours of work

    A contact of mine from Sweden asked me to post this here which I am happy to do - he says he is too tired at the moment.

    Here's part 1 of what the participant said:

     
  2. Dolphin

    Dolphin Senior Member

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    6 minute walking test - results in some other areas

    Somebody sent me this 16 hours ago.
    I thought I'd share it.

     
  3. Dolphin

    Dolphin Senior Member

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    Any normative data for 6 minute walking test for "non-older" healthy adults?

    As I recall, most/all the data so far is for older adults with or without health problems.

    The average age of the participants in the PACE Trial was 38 (SD=12). It'd be good if anyone had could find numbers for that sort of age range.
     
  4. Mark

    Mark Acting CEO

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    I agree; my comment that you quoted was trying to understand what their (spurious) theoretical justification for moving the goalposts was...not agreeing that it was valid! Not sure if I was even right that this was their argument...hard to figure out what on earth this garbage is all about...they must have had some alleged justification, but so far, it seems to be so complicated that nobody understands what it actually was...though it seems perfectly obvious what the real reason was...
     
  5. Marco

    Marco Old blackguard

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    Near Cognac, France


    Reference Equations for the Six-Minute Walk in Healthy Adults
    PAUL L. ENRIGHT and DUANE L. SHERRILL


    Respiratory Sciences Center, University of Arizona, Tucson, Arizona


    Data and age v distance scattergraphs for healthy 40 to 80 year olds


    http://171.66.122.149/cgi/content/full/158/5/1384#F1
     
  6. oceanblue

    oceanblue Senior Member

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    Just to summarise from figure 2, for women only, the typical 6MWD for those aged around 45 (it doesn't go much younger than that) is 600m. Yes, that's a lot more than the sub-400 managed by all the PACE groups at 52 weeks.
     
  7. anciendaze

    anciendaze Senior Member

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    repeated tests + encouragement

    Just in case anyone missed it, the data in the Enright and Sherrill paper refer to 40 to 80 year-olds. The mean age for PACE was 38. There is no reason to expect younger patients to perform more poorly.

    In the summation we find this nugget:
    You can get higher results just by repeating the test! This could account for about 20 m. improvement across the board.

    As for non-standardized encouragement, wasn't that the point of the PACE study? It looks like all PACE data can be explained by subjective changes. The only objective measure was subject to subjective distortion without any real change in condition.
     
  8. Dolphin

    Dolphin Senior Member

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    Also: the full protocol document makes clear that this is the 3rd test patients would have done: at assessment, at 24 weeks (we're not given that data) and at 52 weeks.
     
  9. Marco

    Marco Old blackguard

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    Isn't that the crux.

    CBT and GET groups are told repeatedly that they will get better. SMT and APT groups are not.

    Any wonder the CBT and GET groups do better on the subjective self report 'happy sheets' and a case could certainly be made that the CBT and GET arms both received 'non standard encouragement' prior to the 6MWT.
     
  10. Angela Kennedy

    Angela Kennedy *****

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    Has anybody noticed this little gem from the PACE article about adverse outcomes? (page 12 of the pdf)

    So, we have a rather ad hoc analysis of serious adverse events that 'independent scrutinisers' did not BELIEVE were related to treatment. This needs further investigation.

    On the basis of this vague allusion, ME patients are to accept, on faith, from researchers who do not believe in their illness or the cardiovascular, mitochondrial and neurological impairments that contra-indicate CBT/GET (and ignore the evidence of that completely in their article for that matter), that CBT/GET is safe, and must stop worrying their pretty little heads about it.

    I will look myself anyway- but if anybody can point me towards something I'd be grateful - were treatment drop-outs included in negative outcome figures?
     
  11. Angela Kennedy

    Angela Kennedy *****

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    A separate thread has developed here about Oxford (and other) criteria, their exclusionary capacity and use in the PACE trial:

    http://forums.aboutmecfs.org/showthread.php?10219-PACE-study-and-oxford-criteria

    I don't want to necessarily drag all that information onto this thread as it might become unmanageable. Therefore, I'm just posting that the above thread exists.

    The issue of criteria is very important, and has been since the beginning of the PACE trial. I'm certainly doing some work on it, in addition to: issues of adverse outcome and what I see are discrepant relating of those (leading to this terribly unsafe assertion of safety and efficacy which could have disastrous consequences for many people and must be objected to strenuously in due course); and various other ethical problems (that's a wide ranging group of issues!)
     
  12. Bob

    Bob

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    Yes, it's outragious isn't it.


    Here's the figures for adverse events:

    Serious adverse events

    SMC 7

    GET 17 (This is a 243% increase in adverse events, as compared to the SMC-alone group.)


    Participants with Serious Adverse events

    SMC 4%

    GET 8% (This is a 100% increase in participants with serious adverse events, as compared to the SMC-alone group.)
     
  13. Bob

    Bob

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    This is something i've been trying to get my head around...
    I haven't read the whole paper, or the exact methodology, but it looks to me like they haven't included the dropouts in the figures, because in the Chalder scale figures for CBT, for example, the baseline number of patients was n=161, and then at 52 weeks n=148. So the results were recorded for n=148, not n=161.

    I think that they might also have added more patients to each group, as patients dropped out, so the difference between 161 and 148 might not be the true drop-out rate. I'm not clear on that. Does anyone know about this?

    I've worked out for the chalder scores in the GET group, that if there were only 6 drops outs, as is apparent from the figures in the table 3 (I'm not clear on the number due ot the point i made above), and if we were to assume that each of these drop-out patients recorded a maximum score of 33, then this only changes the total average score by 0.465. But the chalder scale is skewed in favour of the recovering patients, because 33 is the maximum score that extremely ill patients can get anyway, so they only increase their scores by a couple of points if they relapse, whereas those who improve can drop by many points.
     
  14. anciendaze

    anciendaze Senior Member

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    statistical & medical significance

    314 333 312 326 * Baseline
    334 354 379 348 * 52 weeks
    ---------------------

    20 21 67 22 gain

    If we assume 20 meters improvement is merely the result of retest familiarity, or a Hawthorne effect which would not transfer to practice, adjusted scores are less impressive:

    0 1 47 2 adjusted

    What is considered significant improvement on this test for patients with other conditions serious enough to put them in this performance range?

    For COPD patients, 70 meters is suggested (by the ATS guidelines) as showing an intervention produces significant improvement with 95% confidence. For older patients with heart failure, 43 meters was considered significant, though in this case the results proved more responsive to deterioration than improvement.

    The only objective measure, (other than cost,) does not show significant improvement by the standards applied to medical interventions for other conditions which put patient performance in this range. It does show subjective distortion, as should be expected.

    I would like to estimate the effect of parts of the protocol not considered treatment. Adverse events needed to be investigated and reported. Patients were encouraged to remain in the trial, if this did not present a threat to their health -- in the opinion of those running the trial.

    I believe there is a better correlation between these unconsidered interventions and test results than with the treatments under official test. Anyone agree?
     
  15. Bob

    Bob

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    The patients in this study had far more input than any patients would ever have in a normal NHS setting.
    I'm sure that they had many hours of one to one encouragement, that you wouldn't get in a normal setting.
    Does anyone have any insight into how many hours of SMC, GET, CBT and other instructions or encouragement that they had?
    It would be interesting to find out.
     
  16. Angela Kennedy

    Angela Kennedy *****

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    Ooh- thanks for this Bob.
     
  17. oceanblue

    oceanblue Senior Member

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    From memory, there were up to 15 1 hour sessions of CBT, GET or APT, plus I think an average of 3 consultations with the specialist SMC doctor, though I'm not sure if these were also one hour long.
     
  18. oceanblue

    oceanblue Senior Member

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    Very interesting about higher results on repetition. For the record, the protocol does instruct assessors not to encourage patients during the walk itself.
     
  19. Sean

    Sean Senior Member

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    Bedtime here so don't have time to check it further right now, but there seems to be two different tests: a 6 minute walking test (6MWT), and a 6 minute walking distance (6MWD) test. If so then we had better be careful not to mix them up.
     
  20. anciendaze

    anciendaze Senior Member

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    The best match I get for this cohort to patients with other illnesses is from the JAMA paper Dolphin quoted: left ventricular dysfunction

    If I assume the entry criteria selected patients in the first and second quartiles of that group, this looks like a very good comparison. The patients in that referenced study had a mixture of systolic and diastolic dysfunction. Diastolic dysfunction has been reported in long-term ME/CFS patients.

    I need to make it clear that I am not saying any of the PACE patients had congestive heart failure, serious hypertension, ischemic heart disease, etc. If such conditions were known they would have been excluded. I can't say what their ejection fraction (EF) was because this was not measured, since they had passed ordinary screening tests for heart conditions. A standard 6-wire EKG will not normally show diastolic dysfunction with the patient supine. Echocardiograms were not performed, because they were not thought necessary. Similarly, Holter monitoring for 24 hours was not performed.

    If I assume these patients had significant diastolic dysfunction while upright, but did not show other classic signs of heart conditions, this looks like a viable interpretation. I am suggesting they were not merely like patients with left ventricular dysfunction, I am saying they look exactly like a subset of these. Fatigue and dizziness are prominent symptoms for such patients.
     

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