[funny] Cancer-related fatigue, CBT & Actometers. Bleijenberg, etc.

[Esther12]

Maybe not Tig Notaro cancer-funny, but pretty good for an academic paper.

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!).

Examining the role of physical activity in reducing postcancer fatigue

Marieke F. M. Gielissen,

1 Jan F. Wiborg,2 Constans A. H. H. V. M. Verhagen,3 Hans Knoop,2 and Gijs Bleijenberg2
Author information ► Article notes ► Copyright and License information ►
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Abstract

Purpose

Persistent fatigue is a long-term adverse effect experienced in about a quarter of patients cured of cancer. It was shown that cognitive behavior therapy (CBT) especially designed for postcancer fatigue is highly effective in reducing severe fatigue. However, it is unclear by what mechanism the fatigue reduction is reached. In many fatigue reduction programs, an increase in physical activity is assumed to reduce fatigue. The purpose of the present study is to determine whether the effect of CBT on fatigue is mediated by an increase in physical activity.
Methods

Data of a previous randomized controlled trial on the efficacy of CBT for postcancer fatigue were reanalyzed (CBT, n

=

41; waiting list condition, n

=

42). Actigraphy was used to assess the level of objective physical activity. Cancer survivors were assessed prior as well as after the CBT and waiting list period. The mediation hypothesis was tested according to guidelines of Baron and Kenny. A non-parametric bootstrap approach was used to test statistical significance of the mediation effect.
Results

Although CBT effectively reduced postcancer fatigue, no change in level of objective physical activity was found. The mean mediation effect was 1.4% of the total treatment effect. This effect was not significant.
Conclusion

The effect of CBT for postcancer fatigue is not mediated by a persistent increase in objective physical activity.
Keywords: Fatigue, Postcancer fatigue, Activity, Exercise, Cancer survivors, Actigraphy

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:

A previous RCT of our research group demonstrated that cognitive behavior therapy (CBT) especially designed for postcancer fatigue is highly effective in reducing fatigue severity in cancer survivors [5, 6]. In clinical practice, physical exercise is seen as a promising strategy for treatment of fatigue during and after cancer treatment. Because an important element in CBT for postcancer fatigue is a physical activity program, the current study aimed to test a treatment model in which the effect of CBT on fatigue is mediated by an increase in physical activity.

In CBT for postcancer fatigue, an increase in the level of physical activity is stimulated. The fatigued cancer survivor selects a simple physical activity that can be performed every day (e.g., walking or cycling) and increases gradually and systematically the duration of this particular activity. The directive for a patient is to perform an activity twice a day, starting at a level of which is certain that symptoms do not aggravate. Mostly this is 5 to 10 min. The activity level is increased with 1 min a day for each time the activity is performed and will end at a maximum of 60 min twice a day (Table 5). Illness-related cognitions are also targeted during the physical activity program. In particular, patients' preoccupation with their condition and their belief that they have little control over their symptoms are challenged. By the time patients are active 2 h a day, most patients will have become aware of the fact that they are capable of doing more without experiencing extreme fatigue and that they recover faster than before. Gradually, walking or cycling is now being replaced by other activities. One might choose to systematically expand mental and social activities, preparing the patient for a return to work or other personal targets.

Nice they can be certain of this:

If a physician was certain that the fatigue had no somatic cause, the patient was invited to participate.

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):

In understanding postcancer fatigue, it is important to make a distinction between precipitating factors and perpetuating factors. The assumption is that cancer itself and/or cancer treatment may have triggered fatigue (precipitating factors), but that other factors are responsible for persistence of fatigue complaints (perpetuating factors). CBT is focused on six perpetuating factors of postcancer fatigue. They involve insufficient coping with the experience of cancer, a heightened fear of disease recurrence, dysfunctional fatigue-related cognitions, dysregulatory sleep–wake cycles, dysregulatory activity patterns, and insufficient social support and interactions [13].

Worth noting that 'top-up' sessions were available in the second six months:

A mean of 12.5 sessions were given (SD 4.7) with a duration of 1 h during a 6-month period. Patients were offered a maximum of two sessions during a 6-month follow-up period.

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:

Regression analyses testing the hypothesized mediating effect are seen in Table 3. Fatigue was reduced significantly more in the CBT condition than in the control group (path c). However, CBT did not produce a significant change in physical activity (path a). There was also no significant relationship between changes in physical activity and changes in fatigue (path b). The effect of treatment remained significant when it was controlled for changes in physical activity (path c′).

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.

Discussion

The results indicated that the positive effect of CBT on postcancer fatigue was not mediated by an increase in objective physical activity measured with the actometer. CBT did not cause an increase in physical activity at the end of treatment (path a) nor was an increase in physical activity associated with a reduction in fatigue (path b). The finding that there was no effect of the interventions on physical activity already showed that mediation was absent, but as mediation analyses require a large power, a bootstrap analysis was performed. The formal test of the mediation effect confirmed that CBT yielded its effect independent of a change in physical activity. These results are in line with Wiborg et al. [24], who demonstrated that the effect of CBT on fatigue in patients with chronic fatigue syndrome was also not mediated by an increase in physical activity following treatment.

There are several potential alternative explanations for the fact that we did not find support for our mediation hypothesis. One reason could be that the actometer was not obtained from all participants, and it is possible that we introduced a bias through exclusion. Also, by excluding patients, the sample size became smaller. However, no difference on baseline characteristics was found between completers and non-completers, and the effect of CBT was still significant in the smaller group. Additionally, the bootstrap approach is sensitive to detect differences in small samples.

Gradual increase of physical activity is an important part of the treatment protocol; however, no increase was found assessed with actigraphy at the end of treatment. Our study is limited by not documenting the level of physical activity during therapy. Therefore, we do not know whether the patients became temporarily physically more active during CBT. One might assume that this is probable, as they discussed repeatedly their gradual increase in activity with the therapist as demonstrated in Table 5. Anyway, a possible temporary increase was no longer present when the second assessment took place [13].[Patients did also have access to two additional sessions in the second six months, so it seems more likely that patients are just easily encouraged to tell therapists what they want to hear, or else substitute behaviour.]

CBT might have resulted in a temporary increase in physical activity. This temporary increase in physical activity during therapy might have been sufficient to facilitate a persistent change in illness-related cognitions and reduce fatigue. The gradual increase of physical activity can help the patient to feel (more) confident that he or she is actually capable of achieving these activities despite his or her symptoms, thereby enhancing his or her sense of control and bringing about a positive self-efficacy. This would be an interesting hypothesis to explore in future research.

In addition, CBT for postcancer fatigue is also focused on five other perpetuating factors of severe fatigue. It seems logical to assume that the positive effect of CBT on postcancer fatigue was mediated by change in the other perpetuating factors. Future research should therefore be focused on examining the exact mechanisms of change in CBT by monitoring illness-related cognitions and physical activity repeatedly during therapy and on determining the exact role of each perpetuating factor.

The association between fatigue and depression is complex. Fatigue can occur as a symptom of depression or may precipitate feelings of depression because of its interference with mood, work, and leisure activities. However, it is important to realize that in most patients, postcancer fatigue occurs independently from depression [25–27].

The current study sample does not reflect the incidence and types of cancer in the Dutch population, and the sample is quite young compared to the general oncological population. Therefore, a positive effect of physical activity on fatigue cannot be ruled out, and replication is necessary in survivors matching the general oncological population.

In the literature, there is a lack of consistent evidence whether a physical activity program reduces postcancer fatigue [7–12]. Because in the current study we did not find an increase in physical activity, it remains unclear if there is a positive effect of an increase in physical activity for reducing postcancer fatigue.

However, even without an increase in physical activity, CBT was highly effective in reducing postcancer fatigue. Therefore, a persistent increase in physical activity seems not to be a requirement in reducing postcancer fatigue, and a change in illness-related cognitions is likely to play a more crucial role in CBT for postcancer fatigue.

I thought this might be of interest.

PS: Best wishes to all those struggling with cancer or post-cancer fatigue. I ended up on a forum for cancer sufferers who were discussing some research once, and they seemed really pissed off by the way in which their cognitions and behaviours were being medicalised too. For them it was like: 'I've got Cancer! I don't want to have to deal with this shit too! Let me be myself.'

 

[SOC]

Some day the world is going to be laughing at these "think away your symptoms" CBT therapists. Let's hope it's soon.

 

[biophile]

Does it seem unusual to anyone that CBT for post-cancer fatigue and MS is more effective than for CFS? Yes, it would be ironic if after all their consideration for various mediators, they left out multiple forms of reactivity bias. The effects of CBT on fatigue in CFS and possibly other conditions may (largely) be a "laboratory artifact" as XMRV reportedly turned out to be, but unfortunately for us there has been a much longer period of "discovery and de-discovery".

 

[taniaaust1]

However, even without an increase in physical activity, CBT was highly effective in reducing postcancer fatigue. Therefore, a persistent increase in physical activity seems not to be a requirement in reducing postcancer fatigue, and a change in illness-related cognitions is likely to play a more crucial role in CBT for postcancer fatigue.

What's the bet they will be saying the above for us too when they are forced into admiting that CBT doesnt increase our physical activity level at all. They will still be saying it is "highly effective".
I think this shows we will be fighting the idea of CBT being helpful for most of us for a very long time.

 

[biophile]

What's the bet they will be saying the above for us too when they are forced into admitting that CBT doesn't increase our physical activity level at all. They will still be saying it is "highly effective". I think this shows we will be fighting the idea of CBT being helpful for most of us for a very long time.

This has already happened with slightly different wording. The above mentioned paper is an uncanny reflection of several of this group's papers on CBT for CFS, including the same speculation that increases in activity really did occur afterall but just was not measured. Some of it reminds me of what has been labelled as "tooth fairy science":

http://www.skepdic.com/toothfairyscience.html

"Tooth Fairy science" is an expression coined by Harriet Hall, M.D., (aka the SkepDoc) to refer to doing research on a phenomenon before establishing that the phenomenon exists. Tooth Fairy science is part of a larger domain that might be called Fairy Tale science: research that aims to confirm a farfetched story believed by millions of scientifically innocent minds. Fairy Tale science uses research data to explain things that haven't been proven to have actually happened. Fairy Tale scientists mistakenly think that if they have collected data that is consistent with their hypothesis, then they have collected data that confirms their hypothesis. Tooth Fairy science seeks explanations for things before establishing that those things actually exist. For example:

You could measure how much money the Tooth Fairy leaves under the pillow, whether she leaves more cash for the first or last tooth, whether the payoff is greater if you leave the tooth in a plastic baggie versus wrapped in Kleenex. You can get all kinds of good data that is reproducible and statistically significant. Yes, you have learned something. But you haven’t learned what you think you’ve learned, because you haven’t bothered to establish whether the Tooth Fairy really exists.

Furthermore, there may be a simpler, more plausible explanation for your data. (Most readers will not find it arduous to devise an explanation for those gifts that have replaced teeth that were placed under a pillow.)

[...]

But perhaps the most insidious and damaging double-standard that is being advocated under the banner of CAM is a separate standard of scientific research itself. The normal rules of research that have evolved over the last few centuries are being subtly altered or discarded, with clever newspeak. It is a way for proponents to choose their evidence, rather than having the evidence decide [determine?] what works and what does not work.

 

[alex3619]

Tooth fairy science ... like the whole of psychogenic medicine?

 

[Sean]

However, even without an increase in physical activity, CBT was highly effective in reducing postcancer fatigue.

It didn't produce any measurable change in physical behaviour, but a few patients said it helped a bit, therefore it worked very well.

You're shitting me.

 

[Valentijn]

It didn't produce any measurable change in physical behaviour, but a few patients said it helped a bit, therefore it worked very well.

You're shitting me.

You haven't seen this same group's gems about CFS? Exactly the same results and BS conclusions, except that they hid the actometer results in the initial three studies. Better questionnaire responses, no improvement in actual activity levels via actometer, conclusion that "increasing activity doesn't mediate the (presumed) reduction in fatigue".

Aside from the insane conclusions, which imply that questionnaires matter more than actual disability, their papers have been great for us. They prove that CBT/GET do not increase activity levels, even when that is the specific goal of the therapy. Excellent for citing when responding to the PACE crap.

Incidentally, getting the same results in patients with post-cancer fatigue makes me wonder how much else we have in common.

 

[Esther12]

Does it seem unusual to anyone that CBT for post-cancer fatigue and MS is more effective than for CFS? Yes, it would be ironic if after all their consideration for various mediators, they left out multiple forms of reactivity bias.

Yeah - I'm interested in the large improvements in fatigue questionnaires following CBT we've seen elsewhere. The MS study had patients reporting feeling better than healthy controls!

It's also interesting that in these areas, CBT promoters are often a bit more open about the problems with their research. The Chalder MS study talked about response bias. This study is way more open and honest than their CFS one (although still ridiculously evasive).

Even after all the dodgy CFS research I've seen, I think that there's a part of me that still has an instinctive faith that these treatments cannot be total quackery... surely someone would have noticed before now! The more I look at the evidence though, the more it looks like they are just manipulating the way patients answer questionnaires.

 

[Simon]

Much as it's good to see negative results being published as opposed to being buried, I can't figure out why they even ran the analysis.

One of the first step in any mediation analysis is to "Show that the mediator affects the outcome variable"*. In this study, the proposed mediator, increased activity levels, doesn't affect the outcome: fatigue. GAME OVER.

*see mediation guidelines website by Kenny (as in "The mediation hypothesis was tested according to guidelines of Baron and Kenny").

 

[taniaaust1]

You could measure how much money the Tooth Fairy leaves under the pillow, whether she leaves more cash for the first or last tooth, whether the payoff is greater if you leave the tooth in a plastic baggie versus wrapped in Kleenex. You can get all kinds of good data that is reproducible and statistically significant. Yes, you have learned something. But you haven’t learned what you think you’ve learned, because you haven’t bothered to establish whether the Tooth Fairy really exists.

I have to remember that example of things.

 

[Valentijn]

Much as it's good to see negative results being published as opposed to being buried, I can't figure out why they even ran the analysis.

One of the first step in any mediation analysis is to "Show that the mediator affects the outcome variable"*. In this study, the proposed mediator, increased activity levels, doesn't affect the outcome: fatigue. GAME OVER.

Their goal is to show that CBT "works" for cancer (and previously ME/CFS, etc). When the actometers show that the CBT isn't working, they then spin the results. In this case the spin is that they pretend questionnaire responses are the most important outcome measure, and that the actometers are only relevant in showing how CBT "works".

My guess is that this group of researchers is required to use actometers and/or publish results, hence their willingness to go to absurd lengths to show that CBT practitioners are needed to cure fatigue. They will never ever state that "CBT doesn't increase activity levels" - they will twist it to say "Activity levels aren't responsible for decreasing fatigue after CBT."

 

[Esther12]

I didn't think this was worth starting a thread for, but 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 seemed worth posting somewhere.

There's all sorts of annoying stuff is in the BABCP 2012 conference abstracts book:

http://www.babcpconference.com/archive/leeds2012/programme/abstract book v2.pdf

43
A Multivariate Study to explore the involvement of Cognitive and Behavioural factors in Cancer-related Fatigue
Sahil Suleman, Guy's & St Thomas' NHS Foundation Trust; Trudie Chalder, Institute of Psychiatry, King's College London; Kate Rimes, Department of Psychology, University of Bath

Background & Aims: Fatigue is a highly prevalent and debilitating problem in women with breast cancer undergoing chemotherapy. It is becoming evident that psychological factors are more important than illness-related and treatment-related factors when seeking to understand the development and maintenance of cancer-related fatigue. This study investigated the cognitive behavioural, social and affective responses associated with cancer-related fatigue and related functional impairment. Method: 100 women diagnosed with breast cancer completed a range of measures. Correlational and multiple regression analyses were used to explore associations between fatigue severity, social adjustment, physical functioning and a range of psychological, social demographic and clinical variables. 33 patients completed measures prior to chemotherapy and were followed up prospectively to examine the relationship between psychosocial variables and fatigue and functional impairment as measured after three cycles of chemotherapy. Results: A range of cognitive, behavioural and affective variables were associated with increased fatigue severity, poorer social adjustment and increased physical impairment. Key cognitive behavioural correlates included increased embarrassment avoidance (cancer-related) cognitions, all-or-nothing behaviour, avoidance behaviour, health anxiety, unhelpful beliefs about negative emotions and perceptions of punishing responses from their significant other. Furthermore, exploratory analyses suggested that increased presence of maladaptive behaviours and unhelpful cognitions prior to chemotherapy predicted the presence of fatigue and functional impairment after three cycles of chemotherapy.Conclusions: In line with our hypotheses, endorsement of the majority of cognitive, behavioural and affective variables was associated with increased fatigue and functional impairment. Some of these variables also continued to predict fatigue and functional impairment over time. These findings make a significant contribution to a cognitive behavioural understanding of cancer-related fatigue and also point to particular factors that are amenable to change within the context of cognitive behavioural therapy approaches.