Mediators of the Effects on Fatigue of Pragmatic Rehabilitation for CFS

[Esther12]

This paper made me think of CFS research. FINE was published (considering the amount of money and publicity involved, it had to be), but those who have made their careers on the theories tested by FINE seem keen to avoid acknowledging it as a falsification of their claims:

Publication bias remains a controversial issue in psychological science. The tendency of psychological science to avoid publishing null results produces a situation that limits the replicability assumption of science, as replication cannot be meaningful without the potential acknowledgment of failed replications. We argue that the field often constructs arguments to block the publication and interpretation of null results and that null results may be further extinguished through questionable researcher practices. Given that science is dependent on the process of falsification, we argue that these problems reduce psychological science’s capability to have a proper mechanism for theory falsification, thus resulting in the promulgation of numerous “undead” theories that are ideologically popular but have little basis in fact.

Full paper: http://pps.sagepub.com/content/7/6/555.full#aff-2

 

[Dolphin]

The full paper is available free here:
http://www.fine-trial.net/downloads...habilitation for Chronic Fatigue Syndrome.pdf

 

[Dolphin]

There were no between group differences in any of the step test measures at 20 or 70 weeks.

 

[Dolphin]

For completeness and consistency with our published main trial outcome article (Wearden et al., 2010b), all of the above analyses were repeated with the fatigue scale scored 0011. In all of the analyses, the effect of mediators was broadly similar whether the fatigue scale was scored 0011 or 0123.

 

[Dolphin]

our findings do not provide support for the hypothesis that change in physical deconditioning mediates improvement in fatigue.

 

[Dolphin]

When interpreting our findings, it is important to consider the fact that all of the measures (except the step-test) were selfreported, introducing the possibility of common-method variance.

I don't recall coming across the term common-method variance but believe I understand (roughly) this sentence.

 

[Dolphin]

Penultimate paragraph:

The findings of this study have some clinical implications as it appears that change in beliefs about fatigue are an important component of improvement, so therapists should be mindful of this point. In pragmatic rehabilitation, for some patients, modification of beliefs may occur shortly after the initial presentation of the pragmatic rehabilitation model (Chew-Graham et al., 2011). However, it is also possible that change in beliefs occurs as a result of undertaking a gradually increasing program of activities. Patients who have the experience of being gradually more active without any serious deleterious consequences may modify their beliefs about the effects of activity.

The thing is that we don't know for certain the people are actually more active (actometers weren't used). There were no statistically significant difference in the more objective step tests.

Near the start of the discussion, they did mention about the lack of improvement in the step tests:

The finding that there were no differences between the pragmatic rehabilitation and GP treatment as usual groups on the step test variables, is possibly consistent with a recent reanalysis of three trials of CBT (Wiborg et al., 2010). Wiborg et al. (2010) reported that while CBT reduced fatigue, it did not do so via an increase in overall levels of physical activity. This would imply that it may not be necessary for patients to become generally more active and therefore may not be necessary for them to become less deconditioned in order for their symptoms to improve. Indeed, Moss-Morris et al. (2005) reported a lack of improvement in aerobic fitness following exercise therapy in their trial. They noted that where patients did get fitter, this was associated with an improvement in self-reported physical functioning, rather than with improvement in fatigue. In our study, the findings that patients reported they were limiting their activity less, yet they did not improve on the step test, could lead one to speculate that it is in fact change in cognition alone (i.e., change in perceptions of activity), rather than change in behavior which mediates the effect of pragmatic rehabilitation. This would be consistent with Wiborg et al.’s findings that increasing physical activity did not mediate the effect of CBT. Future research involving measures of both cognition and objectively measured activity levels would help to support or refute this interpretation.

 

[Dolphin]

A paragraph from the introduction:

The diagnosis of CFS/ME necessitates the exclusion of other conditions and can leave patients feeling disbelieved (Chew- Graham, Brooks, Wearden, Dowrick, & Peters, 2011) or that they have a poorly understood illness (Chew-Graham, Cahill, Dowrick, Wearden, & Peters, 2008).

Which most people think is true

Subsequently, patients may come to fear that symptoms (e.g., fatigue and delayed onset muscle soreness after exercise) are indicative of damage or relapse

Symptoms can be indicative of relapse. And can certainly indicate something physiological

and therefore avoid factors that exacerbate symptoms such as activity, stress, and other personal triggers (Nijs et al., 2012; Silver et al., 2002).

Most people won't avoid them totally. It's not like a phobia for example.

Most studies have shown that CFS/ME patients are indeed less active than matched nonsymptomatic controls (Evering, van Weering, Groothuis-Oudshoorn, & Vollenbroek-Hutten, 2011).

Which is likely due to the illness. Doesn't prove anything about maladaptive avoidance.
Little evidence that CBT and similar programs reverses this.

According to the pragmatic rehabilitation model, limitation of activity further increases deconditioning and adds to the disruption of sleep patterns, thereby instituting a vicious cycle that is hard for patients to break out of.

Speculative theory - not sure there's much evidence for it.

Additionally, patients who are limiting their activities, either pervasively or intermittently, in response to symptoms (van der Werf, Prins, Vercoulen, van der Meer, & Bleijenberg, 2000) do not get the opportunity to experience the nondeleterious effects of a controlled, gradual increase in activity.

My underlining: where do we have evidence that it's not deleterious.

While not all patients accept the pragmatic rehabilitation model outlined above, the understanding and treatment rationale that it provides can be immensely reassuring for many patients (Chew- Graham et al., 2011).

Any treatment rationale that sounds like it might work can be reassuring. However, if it doesn't work, it is unlikely to be reassuring anymore.
And if one finds out one is being giving a treatment rationale which doesn't match the facts, one doesn't even get temporary reassurance. Also, people may feel guilty for not improving. And other people indeed may see them as being guilty of not trying hard enough if they think people could get better if they just tried harder/similar.

The aim of medicine surely isn't to give people reassuring treatment rationales if they don't work. Any "woo" therapy can also do this. The aim of medicine should be to give accurate descriptions/treatment rationales.

 

[Dolphin]

This is what they say on the main questionnaire that showed mediators:

Beliefs about fatigue and self-reported fatigue management strategies were assessed using subscales of the Cognitive Behavioral Response to Symptoms Questionnaire (CBSQ; Skerrett & Moss-Morris, 2006).

This questionnaire consists of 42 items in the form of statements to which patients indicate agreement on 5-point Likert-type scales.

Items relating to each subscale are summed, with higher scores indicating less adaptive cognitions and behaviors.
Four subscales measured beliefs about the meaning of symptoms:

catastrophizing (e.g., “If I overdo things, I will cause a major relapse”),

fear avoidance (e.g., “I should avoid exercise when I have symptoms”),

embarrassment avoidance (e.g., “I worry that people will think badly of me because of my symptoms”),

and

symptom focusing (e.g., “I think a great deal about my symptoms”).

Two subscales measured patients’ reports of

the extent to which they limited activity to manage their symptoms (e.g., “When I experience symptoms I rest”)

or engaged in “all or nothing behavior”—that is, doing a lot on a good day and resting on a bad day—(e.g., “I tend to do a lot on a good day and rest on a bad day”).

The 42 questions can be found in this attachment: http://epubs.surrey.ac.uk/2788/1/506003.pdf (pages 351 & 352) although it doesn't break them down by category.

 

[Dolphin]

Here are four of the catastrophising questions - somebody may be able to get the others from the link in the last message:

C1 I worry that I may become permanently bedridden because of my symptoms

C2 I think that if my symptoms get too severe they may never decrease

C4 My illness is awful and I feel that it overwhelms me

C6 I will never feel right again

Questions like:

I will never feel right again

seem more like a question about whether one will recover or not. It isn't necessarily a measure of catastrophising to agree with this.
One could certainly fill somebody up with hope that they would improve but in general it's unclear how useful this really is. (in this study, lower scores in the pragmatic rehabilitation scale at 20 weeks was associated with lower fatigue at 70 weeks but a lower fatigue rating "isn't everything").