ME Epidemiology - prevalence, peak ages of onset and gender ratio

I would guard against prevalence rates being uniformly distributed throughout the population. Given that we know certain age ranges have spikes, it may be that these cohorts have greater incidence. Discounting Crawley et al rates of c 2-2.5 % due to general lack of discrimination in diagnosis, International primer for paediatrics suggests 0.5 - 1%, which from memory seems to have come up in other research (can't remember where just now)

The youngest diagnosis I could find on parents groups was 2(!); apart from the teenage spike years there is also a not insignificant number of kids from around age 9 that seem to be affected - perhaps when hormones start kicking off.

There is also the confounding factor of recurrence, which dosn't seem to have much research at all.

 

@Amw66 it is only a rough calculation: there is no point in refining it if my understanding is wrong, and to be honest, there isn't much value in tweaking it all. But different incidence rates with different cohorts will not have a major impact on the overall numbers. Starting at age 12 was just a random thought: my own son went down with it when he was eight.

Recurrence implies recovery, and I am yet to be convinced that anyone recovers from ME. I know people tell me of people that they know have recovered, but out of the hundred (or many more) people that I know with ME, only two went through a stage that they thought was recovery, but turned out to be a patch of remission. I personally prefer the term remission – it reminds folk not to take things for granted should they be so fortunate.

There isn't a goal. I'm just trying to square things in my mind. We seem to need an incidence rate of 0.6% to reach the 250,000 figure, the figure quoted by the charities: an incidence rate of 0.4% brings it down to 180,000: I've seen quotes of 0.2% which would mean 90,000. All that is assuming a trivial or zero recovery rate.

My town has a population of 20,000 so an incidence rate of 0.4% would mean about 56 people having ME, which is possible, but a bit higher than I thought.

You know I'm a geek: playing with numbers keeps me out of trouble.

 

yes, I would agree with remission v recovered- an area that needs some serious research too as there are numerous anecdotes of teenagers " recovering" only to become ill again in later life - it may be valuable to unpick what instigated recurrance - viral/ environmental/etc as it may hold clues for the onset too.
As we know , recovered is a moving target depending on who is defining it.

 

Do you mean a prevalence rate instead of incidence rate? I don't think incidence and recovery are relevant in determining how many ME/CFS patients there are at a certain time point.

If you take 0.4% of 64 million, you get close to 250.000 so I suspect that's what someone did to get to the 250.000 figure (so without taking into account that the 0.4% only applies to the adult population).

 

Does that allow for people who die?

 

That's where my brain starts to get confused. I think I have gone wrong, and need to insert a running total next to column B, and it is that total that represents the number of people infected: the number infected in each age group plus all the people in that age group who were infected at an earlier age.

Not really, but capping the maximum age at 80 is a rough approximation. If I get my head around it correctly, then the next thing I could do is put proper numbers for each age group rather than assume they are all the same, and make some sort of allowance for the numbers of people with ME that die. But to be honest, that is probably more work than is appropriate for the sort of rough calculation I am doing.

 

I have just tried the running total, and that puts the numbers of patients in the millions. There's something fundamental here that I cannot get my head around, and it's frustrating. You need an incidence rate of 0.01% to get the overall numbers down to 166,000.

 

Given we have to rely on subjective reporting of symptoms at present, we can not conclusively distinguish between remission (an ongoing underlying condition that is largely asymptomatic) and recovery (no longer have the underlying biomedical condition).

I was for a couple of years at a level of improvement that I would have at the time described as total recovery. I was conscious of none of the previous symptoms, but was being cautious about building back to my full premorbid activity levels. I was working half time, but took on the renovation of an eight bedroom main house with two associated holiday lets, so though cautious was still doing a awful lot.

My relapse was instantaneous and severe following a very bad dose of seasonal flue over the millennium new year (my millennium bug). And no period of improvement since then has remotely approached something I could subjectively regard as recovery, just partial remission. Interestingly over time relapses have added to my symptom profile and the nature of my current disability could be seen as very different perhaps even qualitatively different to my initial disease.

In retrospect I refer back to that period of being symptom free as remission rather than recovery, however my case could equally logically be described as a period of complete recovery with a second new case of ME triggered by a new infection, or as a period of remission with a relapse triggered by the new infection. Had I had say MS, brain scans might have provided a way of distinguishing between the two, but we do not yet have that option.

In these situations I think it is important to take seriously people’s own account, whilst retaining a degree of skepticism. But ultimately until we have an agreed biomedical diagnostic tool, there will remain a degree of uncertainty.

What we do lack is an accurate set of data: on how many people achieve some degree of recovery/remission, how often they are then totally symptom free or have intermittent symptoms, that allows them to return to their premorbid activity level; on how many people, who believed themselves to be in complete recovery or in a remission that allows a return to ‘normal’ life, have subsequent relapse; what sort of time spans this involves; and how many people have further relapses and remissions after this.

All we can say is that an unknown percentage of people having been diagnosed as having CFS or ME under the current unsatisfactory system will experience some significant degree of remission, with some believing they have had a total recovery. Of these recoveries/remissions a further unknown percentage will relapse and we have no idea what the subsequent course of their condition will be.

Unfortunately most of the current questionnaires do not measure adequately what we as patients would understand as ME, so to do a prospective longitudinal study, or even a retrospective study, require a better way of quantifying our self reported symptoms. Currently in terms of anecdotal evidence we in the ME world are likely to know more people who have relapsed than have continued recovered/in remission. Also in general those that promote their ‘recovery’ are already high profile or have something to sell, so may not be particularly representative.

 

I think it would be fair to say, looking at my calculation and Trish's, than any incidence rate per year above 0.01% would necessitate high recovery rates: ones that are easily visible. Refining the calculation will modify the numbers, but to a mathematician's eye, the figures are in the right ball park.

 

Several posts moved from this thread

The 250,000 figure is way over inflated. See: https://www.s4me.info/threads/non-e...-psychological-me-research.18266/#post-311827 for more discussion on the issue.

 

The 250, 000 pops up in the NICE draft guideline in the "context" section at the end on p71:

https://www.nice.org.uk/guidance/gid-ng10091/documents/draft-guideline

They cite the UK Biobank:

"Recent data from the UK Biobank suggests that there are over 250,000 people in 16 England and Wales with ME/CFS, with about 2.4 times as many women affected as 17 men."

I had not seen reference to the UK Biobank in this context before; thought this was relevant. Are we sure it's inflated in that case?


May be in other places in the document but FWIW in this connection it's also referenced in the draft on p7 and p37 here with a citation:

https://www.nice.org.uk/guidance/gid-ng10091/documents/supporting-documentation-2

"Myalgic encephalomyelitis (ME) and/or chronic fatigue syndrome (CFS) is a poorly understood illness that affects approximately 250,000 people in the UK. It is estimated that around 25% of adults with ME/CFS experience severe symptoms or illness presentation."

"Epidemiological prevalence estimates (that commonly vary between 0.1% to 1%) suggest that there are around 250,000 people living with ME/CFS in the UK. This would suggest that approximately 62,500 sufferers may experience severe illness presentation. A general practice with a population of 10,000 patients is likely to have 30–40 patients with ME/CFS and around half of these are likely to fall into the moderate-to-severe category and may need input from specialist services (Group, 2002)"

 

250,000 just sounded good and there has to be that many worldwide!

I can't help but feel if there were 30 - 40 patients with ME in each practice with 15 - 20 of them moderate to severe then GPs would have a better idea of how the illness impacts people.

I had more understanding that I was genuinely ill from doctors that had known me before than from ones who only know me ill. Especially since women see their doctor often for things like smear tests, pregnancy and then children's ailments GPs should know that something has gone wrong to make them so sick with at least some of the patients. A child they have known from birth who is suddenly confined to bed, a man who has never been ill before, they should have a lot of experience with them.

I think the opposite is true. GPs see people who want to be considered invalids, are always ailing and those who have mental health problems often by the nature of things so it is easy for them to believe that ME is just another form of it.

 

Same - I have one doctor who helps me at the practice and she knew me before. (I am terrified of her retiring). However she also once told me a decade ago that I was the most severe case she had ever seen. This worried me at the time as I was still able to go and see her for appointments and knew there were people much more ill than me (although I was severe and quite unwell). However you only get a tiny amount of time with her and you don't have any time to go into it so she has no idea how it impacts me, really.

I know we have different ideas of what we think of as "severe" but it seems unlikely that there are that many severe patients at my practice, certainly;
she has subsequently said I am an "unusual" case whereas I actually have quite bog-standard boring ME/CFS (I tend to think of EBV history as somewhat of a cliche) and I think this comment was a reference to severity despite the fact that I spent most of the last decade as moderate. (Now severe). I got the sense the other ME/CFS patients (she did make reference to others she had last time I spoke to her!) are less severe and are able to tolerate a different kind of management. She is generally very sensible and quite experienced so I found these comments interesting. Others in the practice have no idea about ME/CFS and one simply laughed at me once telling me it wasn't a real illness, so I do not see anyone else.

 

The 250,000 figure is based on the flawed CDC 1994 criteria. I would estimate that only about 5000 to 10,000 people in the UK have real (exercise harms you) ME. The rest probably have some other fatiguing disorder. Why do you think there are so few ME patients on forums?

 

My memory is that the formal epidemiological study by Nacul, Phebe et al estimated 0.2% for narrow Canadian-type criteria, which would be about 130,000 for UK. Also judging from numbers that I have encountered and GP friends have encountered I think significant long term ME must be present in at least 100,000. I do think the UK Biobank figure may be inflated but not by much more than x2.