The Prevalence of Pediatric Myalgic Encephalomyelitis/Chronic Fatigue Syndrome in a Community-Based Sample (2020) Jason et al.

I agree, this could be at work in the earlier study. Another factor that could be work in the latest study, is we have so many scammers and marketers calling in the US - sometimes 5 or more in a day - that some people don't answer the phone unless they recognize the number

@Michiel Tack - on the high rate of previously undiagnosed patients - I expect there's a range of different factors that could affect that. For instance, I've read that some doctors don't want to give a diagnosis of CFS because they think the patients won't "try" to get better, because they think it might demoralize the patient and leave them hopeless, or because they don't know how to treat it. I've also seen one doctor not want to diagnose it because he viewed Fukuda CFS as a nonsense diagnosis. Finally, I know of one patient that self-diagnosed after a negative reaction to the doctor's prescribed exercise. But even when faced with that information, the doctor did not give this as a diagnosis. Not clear why.

 

Comparison of phone contact/response rate for the new Jason study versus earlier CDC study

Summary (UPDATED): the earlier CDC study was carried out at the time when people were far more likely to pick up the phone and had a screening rate of more than double the Jason study (21% versus 9%). There is a risk in both studies that responders mightbe different from non-responders.

It is also possible, though not definite, that people who didn't respond to the Jason study new the study was about fatigue, which could lead to bias, while non-responders to the CDC study may not have known this, removing the risk of such bias.

And, apologies, I got some of the numbers wrong in my previous post, which I have now deleted.

——

So this is a comparison of the current Jason adolescent prevalence study (published 2020, phone calling may have gone on for quite a few years before that), with the Reyes CDC adult prevalence study (published 2003, phone calls made in 1997). Both our community based samples. The CDC study simply used random digit dialling, while the Jason study bought telephone numbers from InfoUSA.

The key figures are the total number of telephone numbers called, the numbers contacted, and the numbers screened. The Jason approach also needs an adjustment because they were only interested in speaking in detail to households with children/adolescents under the age of 18, while the CDC wanted to talk to every household it contacted.

Jason 2020
148,000 telephone numbers
43,000 contacts (29%)
23,000 households with children contacted
5600 households w. children screened (24%)
Estimate of %age of total households screened (29% X 24%) = 7%

CDC 2003 (Reyes)
116,000 telephone numbers
62,500 households contacted (54%)
34,000 households screened (29%)
Estimate of %age of total households screened (54% ex 29% = 16%

UPDATE: another adjustment is needed as not all the telephone numbers were for households. Some were not working (9% for Jason, unspecified for CDC) and others were for businesses, pagers and, for the CDC study in the 90s, pagers — no figures for these were given in either study. So I'm going to assume that 75% of the total numbers were for residential households.

Adjusting the estimated net contact rate for this gives 21% for the CDC and 9% for Jason studies.

Jason adult 1999 study
28,700 residential households called
18,700 creening questionnaires completed
Net completeion rate = 65%

So the net contact rate for the Jason study was a bit under half that achieved by the CDC roughly 20 years earlier. Even so, both studies screened less than one and five of the people they called and so both are prone to some kind of bias.

It probably helped the CDC being an extremely well-known government agency when you’re trying to get people to answer the phone. The Jason study contacted people in the Chicago area and many will probably have heard of DePaul university, but not quite the same.

When it comes to @Michiel ‘s point about bias because people with fatigue in the family might be more like to answer a survey, that is probably more likely in the new Jason study. First of all, they had a lower contact rate and the answerphone message they left to non-responders probably make clear that it was a study about fatigue (I am waiting for confirmation of this). The CDC paper doesn't say, but other information in the paper suggests it might have been framed as a more general survey about health, and if you are the CDC you probably don’t need to explain as much about why you're calling. So it seems likely there is more scope for such bias in the new Jason study. Whether this was a significant factor or not, we don't know.

 

So since it was a NIH-funded study, can we somehow expect some communication about what is clearly a public health disaster? 95% misdiagnosis rate is just abysmal, though it is of course expected when a disease is maligned and discriminated. Same as most of the disease burden and premature deaths are a direct result of this neglect, this is a choice made with no consideration for the victims and that cannot have any other outcome than massive widespread failure.

Absolutely certain that the wrong framing over chronic fatigue itself plays a huge role in this, deliberately misrepresenting a disease is one sure way of making diagnosis and support almost impossible to achieve. Most people with this disease or with a sick child will run through the list of possible diagnoses and skip over this incompetent and inaccurate definition, just as people would if someone Parkinson's disease was similarly maligned and called "the shakies" instead, or some other insulting nonsense.

Because it just keeps confirming what has been shown time and time again and it dismantles most of the nonsense fiction that has been promoted over the years, stuff like "doesn't affect children" or "mostly a bored middle-aged housewife blues" or "everyone recovers quickly". All of those things have been said by public health agencies and are patently FALSE. That is extremely bad over confidence in public health and medical institutions, that they keep parroting discredited claims and pushing a false illness model that directly harms millions by denying basic medical care and support as a willful choice.

As this grows people really ought to consider what the impact will be on confidence in expertise, same as The Lancet and Richard Horton sparked a global crisis of confidence against vaccination. Experts lying and making stuff up has way more consequences than just on those who are lied to and about.

The effort undertaken here is impressive. This is all information that should be routinely surveiled and compiled but instead researchers have to work around institutions as they cannot be trusted to reliably account for a serious disease disabling millions.

 

Merged thread

https://www.sciencedaily.com/releases/2020/01/200123152453.htm

 

@Michiel Tack - on this point about only 83.3% of diagnosed patients meeting at least one symptom of the PEM DSQ questions - As I understand it, patients might affirm the DSQ questions and yet not have PEM as in the case of someone who is overworking. I also understand that patients might respond the DSQ questions negatively and yet still have PEM - e.g. if someone never overexerts - probably exceedingly difficult.

This study is dealing with kids so the other potential issue is whether they understand the question or are aware of the patterns. Or if the child is very young, the caregiver may have answered and not be fully attuned. But the final diagnosis also involved a clinical assessment and additional questioning which could reveal some of these issues. Since both the Jason Pediatric and IOM criteria were used, I'd assume that 100% of the patients experienced PEM even if the DSQ questions reported less than 100%.

When we proposed the tool to assess PEM as part of NIH's Common Data Elements initiative, we made it a two step process that started with the DSQ questions but then asked the doctor to consider such issues as part of the final diagnosis. I know that some were concerned about the CDE two step approach of having a doctor "override" what the DSQ said. But we just dont yet have a tool to assess PEM that is perfectly sensitive and specific and does not require additional information from the clinical assessment. Emphasizes the need for biomarkers and for educating doctors about how to recognize PEM.

 

More to the point, the DSQ misses important factors that are more useful than things like 'feeling drained after minimum exercise'.

I quite like the way the Bansal Score Chart does it. You need 8 points out of 13, with some kind of PEM. Delayed (>12 hours), prolonged (>24 hours) PEM nabs you 3 points. Where the delay is shorter or the PEM isn't as prolonged, you get 2 points. If the PEM is instant or not very prolonged, you get 1 point.

 

I realise that everyone might be losing interest in the study, but I would really appreciate people's thought on why prevalence for children in this study is much higher than similar studies have found for adults.

Perhaps the most surprising finding of this study is that the prevalence rate of 0.75% is substantially higher than prevalence for adults. One study of adults by the CDC with a similar robust design found a prevalence of 0.24% and another by Jason estimated the prevalence at 0.42%. In this new paper, the authors point out that previous studies of prevalence in young people (with less robust methodology) have generally found lower rates than for adults. They suggest lower prevalencec might be because more children than adults recover, and recover more quickly, reducing the total number of people ill at any one time. However, they don’t suggest an explanation for why prevalence is actually higher in this study than for similar studies of prevalence in adults.

In fact, I think this is the biggest puzzle of the whole study and one would like to get to grips with before I finish my blog.

I guess it is possible that the point made by @Michiel Tack el about families with kids with fatigue beingmore likely take to take part, boosting prevalence, could be right. It is also worth noting that others have argued that parents of children who have ME/CFS (diagnosed or not) have a huge amount to cope with and might be too busy/exhausted to take part in a study like this. Thiswould bias results the other way.

Looking for help here.

 

Here pvfs is quite common in teenagers and many struggle with school.
Key to this is a tight description of PEM.
My son had pvfs, and missed most of a year of school and left early following year. No PEM in terms of fatiguability - totally fatigued, headaches etc , but he would probably gave been captured as ME/ CFS on this .

 

If fulfilment of three case definitions was a requirement to get a ME/CFS diagnosis in this study, we would also expect lower figures than previous prevalence estimates in adults where only fulfilment of the Fukuda criteria was required.

Perhaps it's simply prevalence estimates can only give a very rough estimate and that 0.24%, 0.42% and 0.75% aren't that different given the lack of precision of these kinds of studies.

 

It's heartening, at least, that they compared to three criteria and had specialists assess each person who was deemed likely to have the illness.

I'm not sure all the studies (any?) have been this robust. You'd expect fewer patients to meet all three criteria, but more did. I'd be tempted to assume that previous studies simply weren't robust enough.

Another possibility is that older criteria, by making ME a diagnosis of exclusion, actually lost many 'true' ME patients along the way because they preferred to attribute symptoms to a co-morbidity.

Partially, this may be due to changing clinical attitudes. Maybe clinicians didn't like giving an ME (or CFS) diagnosis if they could at all help it in the past, and this is changing because of greater awareness? Or maybe their biases around aetiology excluded patients who didn't seem to have a psychiatric element? Etc, etc.

Another option is that there's some kind of confirmation bias going on, where clinicians looking for ME see it everywhere, and so ignore other signs that may indicate another, perhaps less obvious, diagnosis. Or perhaps those patients, being younger, haven't yet acquired the telltale markers of other diseases such as lupus, Sjogren's, etc, and so they're being misdiagnosed?

 

I remember it came out that the CDC used a positive Romberg test as an exclusion. I think like you suggest they may have been too willing to exclude some people who had the symptoms.

 

Really? That's quite shocking, to be honest. Do you happen to have a link/source for this?

I thought an exclusion had to be something that can explain the symptoms.

 

I imagine many of us would fail a Romberg. I know I have.

 

https://hqlo.biomedcentral.com/articles/10.1186/1477-7525-1-49
https://hqlo.biomedcentral.com/articles/10.1186/1477-7525-1-49/tables/5

These are called "temporary" exclusions because these were people who had previously been diagnosed with CFS; they were then followed up for up to three years. If at one stage they had any of the above, they weren't
counted as CFS cases. However they were eligible to be invited back the following year.

Looking at now, I'm not sure that hypertension should be an exclusion either.

 

Another CDC paper:

https://bmcneurol.biomedcentral.com/articles/10.1186/1471-2377-4-6
Sleep assessment in a population-based study of chronic fatigue syndrome

• Elizabeth R Unger,
• Rosane Nisenbaum,
• Harvey Moldofsky,
• Angela Cesta,
• Christopher Sammut,
• Michele Reyes &
• William C Reeves

 

Very interesting. Given what we know, hypertension could be undiagnosed OI, abnormal liver function or urinalysis isn't uncommon (it depends how 'abnormal', I guess?), rT3 problems may be more prevalent in ME patients, sleep conditions can be co-morbid according to IOM, and beta-blockers are often given to treat OI symptoms.

I could see why you'd want to be careful in a clinical trial of treatments, but in this sort of study, I think you can afford to be a bit broader.

 

@Simon M - I don't know how typical this would be, but for those sporty families, better knowledge about sports and overall health might make a difference.

One of my best student pals was a rugby player, all his sons played for their region in the usual age groups. As my pal aged he coached.

His eldest son suddenly became unwell in his mid teens. Having had routine blood tests done that didn't show anything much, they decided it was likely a growth spurt and possible overtraining. They immediately restricted him for 6 months- no matches, no exercise beyond the bare minimum necessary, he still managed to get to school but wasn't allowed take part over and above the essentials.

They probably wouldn't have bothered taking part in something like this as they viewed it as a sports issue. Of course they coincidentally did nearly all the right things for an ME patient.

 

Thanks @Dolphin !