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

Sly Saint

Senior Member (Voting Rights)
Abstract
Background

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) has been emerging as a significant health issue worldwide. This study aimed to systemically assess the prevalence of CFS/ME in various aspects of analyses for precise assessment.

Methods
We systematically searched prevalence of CFS/ME from public databases from 1980 to December 2018. Data were extracted according to 7 categories for analysis: study participants, gender and age of the participants, case definition, diagnostic method, publication year, and country of the study conducted. Prevalence data were collected and counted individually for studies adopted various case definitions. We analyzed and estimated prevalence rates in various angles: average prevalence, pooled prevalence and meta-analysis of all studies.

Results
A total of 1291 articles were initially identified, and 45 articles (46 studies, 56 prevalence data) were selected for this study. Total 1085,976 participants were enrolled from community-based survey (540,901) and primary care sites (545,075). The total average prevalence was 1.40 ± 1.57%, pooled prevalence 0.39%, and meta-analysis 0.68% [95% CI 0.48–0.97]. The prevalence rates were varied by enrolled participants (gender, study participants, and population group), case definitions and diagnostic methods. For example, in the meta-analysis; women (1.36% [95% CI 0.48–0.97]) vs. men (0.86% [95% CI 0.48–0.97]), community-based samples (0.76% [95% CI 0.53–1.10]) vs. primary care sites (0.63% [95% CI 0.37–1.10]), adults ≥ 18 years (0.65% [95% CI 0.43–0.99]) vs. children and adolescents < 18 years (0.55% [95% CI 0.22–1.35]), CDC-1994 (0.89% [95% CI 0.60–1.33]) vs. Holmes (0.17% [95% CI 0.06–0.49]), and interviews (1.14% [95% CI 0.76–1.72]) vs. physician diagnosis (0.09% [95% CI 0.05–0.13]), respectively.

Conclusions
This study comprehensively estimated the prevalence of CFS/ME; 0.89% according to the most commonly used case definition CDC-1994, with women approximately 1.5 to 2 folds higher than men in all categories. However, we observed the prevalence rates are widely varied particularly by case definitions and diagnostic methods. An objective diagnostic tool is urgently required for rigorous assessment of the prevalence of CFS/ME.
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.
 
Last edited:
In general, the definitions could be categorized into two groups: the CDC-1994 [22], Australian [25], Oxford [24], IOM-SEID [2] and NICE definitions [29] vs. the Ramsay [21], Holmes [23], ICC 35], CCC [27], PVES [28], and ECD definitions [26]. These two groups overlap in requiring the symptom of cognitive impairment and share the general physical and neurologic symptoms; however, they differ in their inclusion or exclusion of more immune-, neuroendocrine-, and/or autonomic-related symptoms (Fig. 5).
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.
Accordingly, in our study, the prevalence determined with the CDC-1994, Australian, Oxford, NICE definitions were higher (range 1.46–2.52%) than those determined using the definitions CCC, ECD, PVES, and Holmes definitions (range 0.03–0.34%) [36,37,38] (Table 2, Fig. 5). Four studies that independently applied multiple case definitions to the same population all reported considerably higher prevalence based on the CDC-1994, Australian, and Oxford definitions than on the Holmes definition [16, 34, 37, 39].
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?
 
Last edited:
.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.
 
.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.

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

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."
 
Last edited:
What's the difference between the red and blue ellipses?
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.
 
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 get confused by this diagnosis stuff. yet iom seems not.

===

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.

===

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.]

===

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?
 
Last edited:
Letter: Time to correct the record on the global burden of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Maya Vardaman & Stuart Gilmour

Unfortunately, the core figure that is most frequently drawn from the article is a significant underestimate of the prevalence of ME/CFS, and has led to the spread of misinformation about the burden of this disease.
A global ME/CFS population of 17 to 24 million people is reported in articles such as those published in BMC Medicine [2] and Science [3], all referencing Lim et al. [...] The cited reference (reference [14]) is an article about the global burden of multiple sclerosis, and is not relevant to the global ME/CFS population.
The actual headline result of the study by Lim et al. was an estimated prevalence of 0.89% using the CDC-1994 definition, as indicated in the Discussion and Conclusions sections of their article [1]. If we correctly apply this to the global population of 8 billion, the true prevalence of ME/CFS would be 71.2 million (71,200,000).

Link | PDF
 
Merged
Dear Editor,

We have read Lim et al.’s study [1] with great interest. Studies of this illness are scarce, so their article is important in establishing the global prevalence systematically. In fact, it has been cited over 200 times and has had a significant influence on global reporting of the burden of ME/CFS. Unfortunately, the core figure that is most frequently drawn from the article is a significant underestimate of the prevalence of ME/CFS, and has led to the spread of misinformation about the burden of this disease.

A global ME/CFS population of 17 to 24 million people is reported in articles such as those published in BMC Medicine [2] and Science [3], all referencing Lim et al. The same range of numbers is also easy to find in patient advocacy websites and news reports, such as those of the American Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Society [4] and CNN [5], all updated after Lim et al.’s article was published. However, this figure is drawn from the Background section of Lim et al.’s article, where they state, “In worldwide statistics, approximately 1% of the population, 17 to 24 million people, suffer from this condition [14], which is likely to be as common as rheumatoid arthritis” [1]. The cited reference (reference [14]) is an article about the global burden of multiple sclerosis, and is not relevant to the global ME/CFS population.

The actual headline result of the study by Lim et al. was an estimated prevalence of 0.89% using the CDC-1994 definition, as indicated in the Discussion and Conclusions sections of their article [1]. If we correctly apply this to the global population of 8 billion, the true prevalence of ME/CFS would be 71.2 million (71,200,000). However, new research using more up-to-date datasets and methods is essential to gain a full understanding of the burden of this disease.

Due to this unfortunate misreading and misattribution by others of an erroneous reference in the Background section of Lim et al.’s article, there is widespread underestimation of the true burden of ME/CFS. Such underestimation may exacerbate the isolation, stigmatization, and suffering of people living with this poorly-understood and under-recognized illness. More effort is needed to correct this underestimation globally, develop treatment methods and welfare support, and relieve the burden of ME/CFS. Correct reporting of the true prevalence of this disease is an important first step to addressing the ongoing neglect that its sufferers experience, and this can begin with the correct reporting of Lim et al.’s research.
LINK
 
Last edited by a moderator:
The CDC study on the Georgia cohort (Reeves et al., 2007) nominally uses the Fukuda criteria but it uses a weird operationalisation of the criteria. I think it should be ignored (found a prevalence of 2.54%).
 
Back
Top Bottom