Systemic exertion intolerance disease diagnostic criteria applied on an adolescent chronic fatigue syndrome cohort - Wyller et al (2018)

[alex3619]

I do not see any attempt to detect PEM. If they did not assess for PEM, they cannot possibly apply the SEID criteria since they require PEM to be present for a diagnosis.

This is the fundamental problem for SEID. However this problem applies to all ME definitions. When studies are done its important to know how a PEM finding is operationalised. This is where a lot of research is probably failing. We need a reliable PEM biomarker. The 2 day CPET might work but is problematic for some patients. The nanoneedle test, still in early development, might work too, as might other blood markers. In the meantime there is no substitute for detailed in-person questioning to try to determine PEM. The big issue here is how do we distinguish PEM from exercise intolerance in all patients?

 

[alex3619]

If the finding that adolescents meeting SEID criteria have higher depressive symptom scores than those who are simply chronically fatigued is reliable (and I’d want to see it replicated in a non-retrofitting study), well, that wouldn’t be surprising to me. Wouldn’t we expect patients who are more symptomatic to potentially have a greater emotional impact?

One of the issues here is that the depression questionnaires probably have low specificity. They can easily pick up ME symptoms and score them toward depression, even if the patient is not depressed. Like ME there is no diagnostic biomarker for depression.

 

[Dolphin]

There were quite a number of P values less than 0.1. And some less than 0.05.

So there were other differences between the groups, though the differences weren't considered statistically significant.

But generally it looked like the SEID group tended to be more severely affected (when they were assessed at baseline).

Sample finding
Patients with CFS:
School absence, %, median (IQR)
SEID-negative (n=69) 50.0 (65)
SEID-positive (n=45) 75.0 (65)
baseline Difference/OR 25.0
95% CI of difference/OR 0.00 to 37.5
P value 0.069

 

[Dolphin]

The review history is here, though I didn't find it particularly interesting on this occasion:
https://bmjpaedsopen.bmj.com/content/bmjpo/2/1/e000233.reviewer-comments.pdf

One of the reviewers is Esther Crawley.

 

[Dolphin]

The review history is here, though I didn't find it particularly interesting on this occasion:
https://bmjpaedsopen.bmj.com/content/bmjpo/2/1/e000233.reviewer-comments.pdf

One of the reviewers is Esther Crawley.

Not particularly interesting perhaps, but she said these 2 things:

I have a few minor comments: The paragraph in the introduction needs to be softened: “The pathophysiology of CFS remains poorly understood, but multiple studies have demonstrated certain characteristics such as: Attenuation of the hypothalamus – pituitary – adrenal axis (HPAaxis)[8,9] which may be associated with PEM,[10] altered autonomic cardiovascular control,[8,11,12] and impaired cognitive function

In the introduction please delete "Despite ample research". There is good evidence that there is insufficient research, particularly for biomarkers.

 

[Snow Leopard]

In the introduction please delete "Despite ample research". There is good evidence that there is insufficient research, particularly for biomarkers.

Wow, that shows substantial bias on the part of the authors right there. Glad Crawley called them out on that one.

 

[Esther12]

Wow, that shows substantial bias on the part of the authors right there. Glad Crawley called them out on that one.

In some ways, I feel it would have been better for us if researchers did not have to go through peer-review, but could present their own views more openly.