Discussion in 'Health News and Research unrelated to ME/CFS' started by Andy, Mar 14, 2018.
Open access at https://www.nature.com/articles/s41598-018-20993-y
Fascinating. So even when patients are told they are taking a placebo, they report less fatigue after 21 days, and this is maintained over the next 21 days after stopping the placebo.
It would be interesting to use a more objective measure such as actometer, and to do a long term follow up. I don't think the questionnaires they used would have picked up whether there were able to function better.
So the question in my head is, are they really less fatigued after taking the placebo, or is there some way it is fooling them into thinking they are less fatigued and filling the questionnaires in differently?
It reminds me of the asthma study where patients on placebo thought they were less breathless, but objective spirometer readings showed the asthma was really just as bad.
Due to this, doesn't it mean that the PACE results are even more useless than we thought anyway? That even when people are given something that doesn't work, they still report that they are less fatigued? All this shows surely that questionnaires are likely to encourage people to report they are better than they were previously.
Absolutely bang on right Andy. It shows that people report feeling better simply because that is their role in a charade.
Yet again we see a study conclusion that indicates that the authors do not a have a scrap of common sense.
Neither, it is fooling them into playing a charade.
It is really quite an elegant study in that respect.
Like the SMILE trial it is another sort of positive control for PACE showing that if you tell people that their role is to say they are better they probably will.
You just need to skim the "Study Procedures" section to demonstrate the points made above, and the "PI delivered these discussion points in a way that fostered emotional support, hope and trust." and "we comfortably acknowledge disbelief is understandable and encouraged them to 'see what happens.'"
As to figures of improvement reported in the Abstract, together with a brief read of rest of paper, I'm pretty sure I don't need to be a statistician to see the potential for 'massaging' them for maximum impact .. so I didn't go to the trouble. All the stats 101 lessons I find here on the forum in abundance .. must be rubbing off on me.
Wishing everyone improved health and every happiness. John
I think this was entirely deliberate. The PI is an "oncology health behaviour specialist". So I think they purposefully did everything they could to maximize the conceptual impact on participants to maximize the apparent resulting effects.
One of the authors of this paper was interviewed a couple of years ago:
Yeah, Kaptchuk is a big promoter of the 'powerful placebo'.
This placebo study does look interesting. I've not had a chance to look at the paper yet but it sounds like it could be useful.
I thought I'd post some old notes about a biopsychosocial cancer fatigue study here.
This one from Knoop and Bleijenberg:
Results are the same as for CFS, with CBT leading to improvements in questionnaire scores, but not objective measures of illness. They're more open about this being a problem than they were with their CFS results, but still try very hard to avoid mentioning even the possibility that their questionnaires are not reliable measures of outcome for cognitive or behavioural interventions (and succeed!).
Full paper: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3360858/
I picked some bits out, but it's quite a short paper, so people might prefer to just read it themselves.
Couple of bits making it clear that, if CBT were working as intended, activity levels would increase:
Nice they can be certain of this:
Looks like the control was waiting list only, so lots of room for response bias.
Again they decide to assume that perpetuating factors are entirely reversible and cognitive/behavioural, based on.... wish thinking? (pragmatism):
Worth noting that 'top-up' sessions were available in the second six months:
For those of you really interested in mediation analyses, there's a fair bit of it, and I'm too tired to dig into that right now (someone explained bootstrapping to me... I understood it for a bit!).
No significant relationship between changes in physical function, and changes in fatigue questionnaire scores:
I'm going to post all of their discussion, because it's a bit funny to me that they explore so many possibilities, without ever considering whether their highly effective cognitive-behavioural treatment might just be inducing response bias when compared to a waiting list control. We have no evidence that fatigue questionnaires are reliable ways of assessing cognitive and behavioural interventions.
Also, they keep trying to come up with ways in which patients could have increased their activity... but that just didn't show up.
There's also this 2012 presentation from Chalder and Kathering Rimes that claimed psychological factors were more important than illness or treatment related factors for cancer related fatigue. That claim seems a bit premature to me.
http://www.babcpconference.com/archive/leeds2012/programme/abstract book v2.pdf
For a while, lots of my friends with MS were taking part in clinical trials. As they discussed them, it became clear that "a little bit better" is where the placebo effect occurs. None of them wanted to dismiss a possible treatment out of hand so if it did not actually make them throw up or fall over or something they answered this way.
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