Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), Eun-Jin Lim et al, Feb 2020

full paper here
https://link.springer.com/article/10.1186/s12967-020-02269-0

 

I see one of the studies they used was Reeves et al 2007. This used the so-called empiric criteria for CFS (Reeves et al, 2005), which are really rubbish. It found a prevalence of 2.54%.

Edited to add:
The Reeves et al 2005 criteria are an operationalisation of the Reeves et al 2003 criteria which are basically a version of the Fukuda 1994 criteria.

 

The venn diagram in Figure 5 is funny, shows the mess of case criteria based simply on symptom lists.

https://link.springer.com/article/10.1186/s12967-020-02269-0/figures/5?shared-article-renderer

 

Agh! I wish they had separated the definitions according to whether PEM is a required criterion. This would have been informative, though I'm not sure many studies have used the IOM, CCC or ICC criteria.

Is the Holmes (CDC-1988) definition much different than Fukuda (CDC-1994)? Both list PEM as a minor symptom after all.

ETA: in a nutshell, Holmes seems to be Fukuda minus PEM but with more exclusions and many more "minor" symptoms. So in the absence of these symptoms -- even though they're not required -- I suppose that patients and clinicians alike would tend to investigate another diagnosis than CFS, thus leading to a lesser prevalence w/ Holmes?

 

.9% is about triple the prevalence of MS and about 2X the prevalence of RA. There’s maybe 15-20 drugs available for these 2 diseases combined. If the prevalence of MECFS was this high pharma would be going crazy to get drugs approved for this disease.

https://n.neurology.org/content/92/10/e1029

https://www.ncbi.nlm.nih.gov/m/pubmed/28455559/

 

There are not easy targets with this illness yet as the pathophysiology is not understood.
So the drug companies are reluctant to invest at this time.

I think whatever the true prevalence is, the illness is significant enough that there is a big drug market there.

We just need to seek to ensure that the basics are understood more which will require more public and private funding.

 

Most of the work identifying drugs and drug targets is not done by pharmaceutical companies, who basically wait until most of the research is already done before jumping in and figuring out how a drug can be manufactured on an industrial scale.

 

https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-020-02269-0/figures/5

Neat diagram showing the over lapping criteria and symptoms of ME.

 

That's an interesting picture. I think the IOM artificially overhangs the left-hand side of the diagram, because it more accurately covers the section where nearly all the criteria overlap (check the symptoms in that space and you'll see what I mean).

I'd be interested to see where the NICE 2021 criteria fit. I think it would cover the existing middle space but also stretch further to the right because of the optional secondary criteria. As a result, I think it would cover a larger section of overlap between all the criteria, with a skew to the right-hand side where the ICC, CCC and PVES criteria are.

 

What's the difference between the red and blue ellipses? At one time or another since onset, I think I've had nearly every symptom on that chart except for "motor disturbances" and "genito-urinary symptoms."

 

I don't know but I think there should be a new criteria that exclusively includes patients who have an adverse reaction to exercise and exertion (real ME).

Diluting the inclusion criteria harms credibility and renders research meaningless or even counter productive. £1,000,000's have already been lost to junk research that include any fatigue patients and implies that exercise can't harm ME patients or that it's beneficial.

 

The problem with that is most diseases people feel worse with exercise and have a flare up of symptoms.

The difference with ME is that the consequences of exercise are different so we have an abnormal response to exercise that is not logical. Walking can make our eyesight go for instance or reading a book can make it hard to walk.

Also the amount of exertion is minimal with excessive consequences, then it takes an abnormally long time to recover with even months or years not unusual.

The most important difference is it is possible to have no consequences of exertion or awareness you have done too much until up to three days later.

Unfortunately, even those who should know better say that PEM is a flare up of symptoms with exertion making it a common sign of disease. I sometimes wonder if you have to experience it to really understand.

 

i get confused by this diagnosis stuff. yet iom seems not.

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when the iom flowchart was published, i thought it might or might not be accurate and accessible, but would a physician think to use it?

does it jump out when you have nearly every symptom on the chart? i thought no at the time. i thought it might be buried under what the pwme is telling the physician, even if the physician knows to pull the flowchart out.

it might be common for even specialists to be overwhelmed by big lists of symptoms and signs and even stop reading.

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do we even know if subsets of e.g. dysautonomia or mcas communities are m.e. with a different label?

imo astonishing diversity of opinion on pem. do scientists currently have consistent operationalization? does pem in severe look like pem as usually defined? yet considered practically pathognomonic. maybe pem is triggered by insults to body. is immediate pem distinctive?

the clinicians coalition thing says immediate pem is possible. and it is kind of hte case with me.

sle and possibly others [lyme?] can supposedly imitate. what if you have almost everything on the chart + more + anti-ds dna which is highly specific for sle? [i heard there's a tv guy who says it's never lupus but i also heard the same guy prescribed cbt/get.]

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then there are confusing (to me) claims about misdiagnosis like 40% by mea or nath. what diseases are the true diagnoses when the highly multisymptom are misdiagnosed as m.e.?

there is a list of conditions in "Table 3 Medical Conditions That Present Similarly to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome" in https://www.mayoclinicproceedings.org/article/S0025-6196(21)00513-9/fulltext

are any of those plausible misdiagnoses for those who are highly multisystem and meet iom or the clinician coalition thing (which refers to iom)? perhaps those are for edge cases when you have a competent physician.

where do the misdiagnoses come from in the nih clinical center? what failings or subject "edges" led to them?