What is in a name? Comparing diagnostic criteria for CFS/ME +/- Fibromyalgia

[Simon]

What is in a name? Comparing diagnostic criteria for chronic fatigue syndrome with or without fibromyalgia
Meeus M1, Ickmans K, Struyf F, Kos D, Lambrecht L, Willekens B, Cras P, Nijs J

Abstract
The current study had two objectives.
(1) to compare objective and self-report measures in patients with chronic fatigue syndrome (CFS) according to the 1994 Center for Disease Control (CDC) criteria, patients with multiple sclerosis (MS), and healthy controls,
(2) to contrast CFS patients who only fulfill CDC criteria to those who also fulfill the criteria for myalgic encephalomyelitis (ME), the 2003 Canadian criteria for ME/CFS, or the comorbid diagnosis of fibromyalgia (FM).

Method
One hundred six participants (48 CFS patients diagnosed following the 1994 CDC criteria, 19 MS patients, and 39 healthy controls) completed questionnaires assessing symptom severity, quality of life, daily functioning, and psychological factors.

Objective measures consisted of activity monitoring, evaluation of maximal voluntary contraction and muscle recovery, and cognitive performance.

CFS patients were screened whether they also fulfilled ME criteria, the Canadian criteria, and the diagnosis of FM.

Results
CFS patients scored higher on symptom severity, lower on quality of life, and higher on depression and kinesiophobia and worse on MVC, muscle recovery, and cognitive performance compared to the MS patients and the healthy subjects. Daily activity levels were also lower compared to healthy subjects.

Only one difference was found between those fulfilling the ME criteria and those who did not regarding the degree of kinesiophobia [fear of exercise] (lower in ME [but difference was small]), while comorbidity for FM significantly increased the symptom burden.

Conclusions
CFS patients report more severe symptoms and are more disabled compared to MS patients and healthy controls.

Based on the present study, fulfillment of the ME or Canadian criteria did not seem to give a clinically different picture, whereas a diagnosis of comorbid FM selected symptomatically worse and more disabled patients.
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Guess it's not so surprising that having Fibromyalgia as well as CFS/ME is associated with worse symptoms. The sample was pretty small for comparing subgroups of CFS (Fukuda, ME, CCC) though the differences between the groups looked small: - see supplementary material for data

 

[A.B.]

Definitions that require additional physical symptoms compared to the Fukuda definition should select sicker patients. Something isn't right here.

Edit: it seems that these are researchers coming from a biopsychosocial point of view, which of course tends to argue that all CFS is the same. In the absence of objective tests, bias is inevitable, and that's probably what is happening.

 

[Anne]

I also thought the abstact of this weird. Has anyone looked into the study?

 

[Anne]

@Simon @Mark @Dolphin

Have you looked into this study a bit more? Strange that they didn't find more differences between the wider CFS criteria and the narrow criteria such as CCC. I also wonder how they defined and measured “kinesiophobia” (that problematic term)

 

[Valentijn]

Have you looked into this study a bit more? Strange that they didn't find more differences between the wider CFS criteria and the narrow criteria such as CCC. I also wonder how they defined and measured “kinesiophobia” (that problematic term)

These researchers wouldn't recognize "science" if it jumped up and bit them on the nose. They have a history of using useless tools to measure activity levels, and heavily spinning their results. I wouldn't expect anything intelligent to come from them, or from their research.

 

[WillowJ]

Have you looked into this study a bit more? Strange that they didn't find more differences between the wider CFS criteria and the narrow criteria such as CCC.

I'm none of the people you asked, but I'll give it a go...

CFS patients were screened whether they also fulfilled ME criteria, the Canadian criteria, and the diagnosis of FM.

It looks to me (just from this wording in the abstract) like they pulled a PACE and used Oxford first, then classified the Oxford patients according to whether they also fit other criteria, rather than appropriately using each ICF, ME, or ME/CFS definition to be studied "from scratch".

That could be a legitimate way to study FM if interested in it solely as a comorbid condition, but to compare and contrast Oxford, ICC, and CCC, each of those has to be independently applied to the same sort of population (not one first pre-screened to fit their favored definition).

 

[Valentijn]

Based on the supplementary data at http://static-content.springer.com/.../MediaObjects/10067_2014_2793_MOESM1_ESM.docx there were quite a lot of differences between CCC and non-CCC Fukuda patients. But because it was a very small study (48 patients) none were capable of being statistically significant.

They also don't break down the SF-36 subscores, which is somewhat suspicious.

But basically the CCC group scored quite a bit higher for physical symptoms, and the non-CCC group scored quite a bit higher for personality disorders and mood swings.

Funny how they never mentioned that they found almost-significant results for a dozen or more symptoms and correlates, and that they badly need reproduction in a bigger group to be able to determine if there is or isn't actual significance.

 

[Dolphin]

It looks to me (just from this wording in the abstract) like they pulled a PACE and used Oxford first, then classified the Oxford patients according to whether they also fit other criteria, rather than appropriately using each ICF, ME, or ME/CFS definition to be studied "from scratch".

That could be a legitimate way to study FM if interested in it solely as a comorbid condition, but to compare and contrast Oxford, ICC, and CCC, each of those has to be independently applied to the same sort of population (not one first pre-screened to fit their favored definition).

Correct except that instead of everyone having Oxford, everyone had Fukuda.