Long-term follow-up after cognitive behaviour therapy for chronic fatigue syndrome

A.B.

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Long-term follow-up after cognitive behaviour therapy for chronic fatigue syndrome
Anthonie Janse, Stephanie Nikolaus, Jan F. Wiborg, Marianne Heins, Jos W.M. van der Meer, Gijs Bleijenberg, Marcia Tummers, Jos Twisk, Hans Knoop

Cognitive behaviour therapy (CBT) is an effective treatment for chronic fatigue syndrome (CFS). Main aim was to determine whether treatment effects were maintained up to 10 years after treatment.

Participants (n=583) of previously published studies on the effects of CBT for CFS were contacted for a long-
term follow-up assessment. They completed questionnaires on main outcomes fatigue severity (CIS) and physical functioning (SF-36). The course of these outcomes since post-treatment assessment was examined using mixed model analyses.

Between 21 and 125 months after finishing CBT, 511 persons (response rate 88%) completed a follow-up assessment. At follow-up, mean fatigue severity was significantly increased to 37.60 (SD = 12.76) and mean physical functioning significantly decreased to 73.16 (SD = 23.56) compared to post-treatment assessment. At follow-up still 37% of the participants had fatigue scores in the normal range and 70% were not impaired in physical functioning. Positive effects of CBT for CFS on fatigue and physical functioning were partly sustained at long-term follow-up. However, a subgroup of patients once again reported severe fatigue, and compromised physical functioning. Further research should elucidate the reasons for this deterioration to facilitate the development of treatment strategies for relapse prevention.
Some people commented on the study on Twitter:




http://dx.doi.org.sci-hub.cc/10.1016/j.jpsychores.2017.03.016
 

Dolphin

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Seems these authors are in on the same game as the PACE authors in fudging thresholds.
This paper uses a threshold for fatigue of 35+.

In the abstract, this is called a threshold for "severe fatigue". However scores lower than that are also called "fatigue scores in the normal range"

Here is something Andrew Kewley wrote on this which regards to another paper by some of the same team:

https://www.ncbi.nlm.nih.gov/pubmed/28265678#cm28265678_65392

However the claims made in the abstract refer to healthy ranges, but this is not the same as "severe fatigue" as operationalised by a CIS-fatigue score of less than or equal to 35.

The healthy ranges are instead provided by another study which has also been cited: 41. Vercoulen JH, Alberst M, Bleijenberg G. The Checklist Individual Strength (CIS). Gedragstherapie. 1999;32:131-6.

That study found in a group of 53 healthy controls (mean age of 37.1, SD 11.5) had a mean CIS-fatigue score of 17.3 (SD 10.1). This would provide a cut-off for the "healthy range" of ~27. The manuscript of the present RCT does not provide the results of how many patients met this cut-off score.

Also of note, in a study co-authored by one of the authors of the present study utilised a threshold for a "Level of fatigue comparable to healthy people" as less than or equal to 27.

See: Knoop H, Bleijenberg G, Gielissen MFM, van der Meer JWM, White PD: Is a full recovery possible after cognitive behavioural therapy for chronic fatigue syndrome? Psychother Psychosom 2007; 76: 171–176.

Therefore the claim made in the abstract of patients reaching "a fatigue level within the range reported by healthy persons" is not based on evidence provided in the manuscript, or is simply incorrect. I ask the authors to provide the results of how many patients in both groups met the criteria of having a CIS-fatigue score of less than 27.
 

Dolphin

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Plenty of material here to respond to if anyone is inclined:

http://www.jpsychores.com/content/authorinfo

Letters to the Editors

These normally refer to articles previously published in the journal. The Editors are also willing to consider letters on subjects of direct relevance to the journal's interest, including research letters. Letters should not exceed 1000 words, including references. Where appropriate, they should begin with a reference to the published article that is the subject of the letter. Research letters should be submitted as 'Letters to the Editors'
 

Dolphin

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This paper uses a threshold for fatigue of 35+.

In the abstract, this is called a threshold for "severe fatigue". However scores lower than that are also called "fatigue scores in the normal range"

Here is something Andrew Kewley wrote on this which regards to another paper by some of the same team:

https://www.ncbi.nlm.nih.gov/pubmed/28265678#cm28265678_65392
They do do a new analysis of fatigue scores in this study which does get you have around 35 (indeed mean +1 standard deviation = 38.52):
Participants’ fatigue scores at long-term follow-up were significantly higher than the general population scores (M = 37.60, SD = 12.76 compared to M = 26.69, SD = 11.83, p < 0.01).
the mean fatigue score at long-term follow-up were compared with a sample from the Dutch general population matched for age and gender using Chi-square tests and a t-test for independent samples. The controls were gathered from a cohort (N=2294) of panel members of CentERdata, a Dutch research institute at Tilburg University consisting of Dutch households representative of the Dutch population.
They never say that these are healthy people however.
 

RogerBlack

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They never say that these are healthy people however.
Unless you're excluding the same illnesses in your cohort of CFS patients as you exclude in determining 'healthy' people, it would be wrong to compare to healthy people.
You want (ideally age-matched) controls of similar health other than CFS.
 

Dolphin

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For CFS, several studies that investigated short-term treatment effects found sustained effects up to eight months after the end of treatment [13-15]. Two studies had a longer follow-up period [16, 17]. In the smaller study of Deale et al. [16], most patients reported sustained improvement at five-year follow-up. However, significantly more patients were severely fatigued and fewer patients reported good physical functioning at long-term follow-up compared to short-term follow-up. More recently, Sharpe et al. [17] found sustained positive effects of CBT on fatigue and physical functioning at a median follow-up period of 19 months.
They don't mention the results here for the control group:

In Deale et al., the percentage with CFQ <4 was exactly the same as the CBT group.
There wasn't a statistically significant difference in terms of who scored >83 on the SF 36 PF (48% vs 32%). Slightly fewer people scored <4 on General Health Questionnaire following CBT versus controls (48% versus 54%). On the clinical global inventory, 68% marked themselves as much better or very much better following CBT compared to 36% in the controls..

In Sharpe et al., there was no statistically significant difference for CBT over the no individualised therapy group for both fatigue and physical functioning.
 

Dolphin

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Some results from the text:

Mean age at long-term follow-up was 44.5 years (SD = 11.0), 388/ 511 (76%) of the sample was female, 264/ 490 (54%) had paid work, 114/ 430 (27%) received a disability pension,
Mean scores at long-term follow-up on the SF-36 mental health and bodily pain were 67.39 (SD=17.83) and 62.35 (SD=27.21), respectively.
 

Dolphin

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This is interesting. There is no mention of this bias in the abstract.
Comparison of participants with non-participants

At pre-treatment assessment the follow-up participants did not significantly differ from nonparticipants regarding mean age, fatigue severity and physical functioning. At post-treatment assessment, the non-participants (n=72) scored significantly higher on fatigue severity (M=36.05, SD=14.13 compared to M=29.74, SD=13.80, p<0.01) and lower on physical functioning (M=67.93, SD=23.86 compared to M=79.53, SD=20.63, p<0.01) than the followup participants. At short-term follow-up assessment, the difference between both groups was still significant for physical functioning (M=75.69, SD=20.12 compared to M=83.40, SD=19.06, p=0.04) but not for fatigue.
Another limitation is that the non-participants had on average worse post-treatment outcomes when compared to the post-treatment scores of participants. This could have introduced a selection bias. Furthermore, the short-term follow-up assessment had the highest number of missing values. The mixed-model approach is able to handle missing values [29], but it is conceivable that those patients who were dissatisfied with CBT would choose not to complete the short-term follow-up measurement, leading to only positive mean values at short-term follow-up. As such, this possibility indicates that our sample was perhaps not completely representative for the population of CFS patients who received CBT, and, therefore, our results might be too positive with regard to the course of CBT effects.
 
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Dolphin

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By including time as a categorical variable, comparison of post-treatment assessment with short-term follow-up showed no significant difference in fatigue or physical functioning. At long-term follow-up fatigue severity significantly increased (mean change 7.30, p<0.01) and physical functioning significantly decreased (mean change -6.21, p<0.01) compared to posttreatment assessment.
Comparison of the percentages of patients scoring outside the normal range of fatigue and physical functioning between post-assessment and short-term follow-up showed a small but significant increase for fatigue [beta 0.40, p < 0.01, Odds Ratio (OR) 1.49] but not for physical functioning. At long-term follow-up the percentages of patients scoring outside normal ranges were significantly higher for fatigue (beta 1.43, p < 0.01, OR 4.18) and physical functioning (beta 0.84, p < 0.01, OR 2.31) compared to post-treatment assessment.
 

Dolphin

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A significantly higher percentage of the population controls scored within the normal range of fatigue (72% compared to 36.8%, p < 0.01) and had paid work (69.7% compared to 53.9%, p < 0.01).
At long-term follow-up, it was unclear how many hours people worked and whether the presence of severe fatigue was the reason for not having paid work.
It would have been interesting to have known more about people's work status. My guess is a lot of the CFS people were not working full-time.
 
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Dolphin

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Depression research has shown that persons who had a depressive episode remain sensitive to the development of depressive symptoms, even after successful treatment [32]. The same seems true for CFS. Even if fatigue, the central symptom of CFS, can return to normal levels after CBT, the presence of episodes of severe fatigue and physical impairment might be a recurrent condition for a substantial subgroup of patients. For depression and chronic pain, interventions have been developed in order to maintain effects of behavioural therapy [11, 12][33]. For CFS such interventions are not yet available, but it is advisable that they will be developed and tested for their efficacy.
Something to look forward to … not.
 

Dolphin

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A limitation is that the outcome variables were restricted to fatigue severity and physical functioning. Although these are central features of CFS and the two main outcome measures in most follow-up studies in the field, other characteristic symptoms exist, like post-exertional malaise. We did not collect data on the course of these other symptoms.
 

Dolphin

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I'm not sure if that has been explicitly mentioned before in this thread, but the big issue with this study is we don't now how a similar group who didn't have CBT would have fared.
 

Keith Geraghty

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the small drop in physical function with increasing fatigue ie those recovered are having more fatigue as time goes on - just doesnt add up; CFS patients experience clear problems with physical function and social function and fatigue --- one wouldnt fall without the other

when it doesnt add up.....?