Why so little focus on Functional Disability and so much focus on “Symptoms”?

[Yann04]

I feel like the discourse, the research, and pretty much everything and anything around Long COVID and ME focuses on the “symptoms” and not the functional disability.

I am not disabled by symptoms alone; I am disabled by a profound functional limitation driven by post-exertional malaise (PEM). The primary barrier isn’t the severity of individual symptoms but the inability to exert beyond a narrow threshold without severe consequences.

A lot of discourse and people talking about the disease focus on symptoms, and their severity, while nearly ignoring an aspect of functional disability. Even studies trying to characterise the disease or outcome measures for trials sometimes seem to forget the “disability” part and focus on the patient’s symptoms, which doctors often frame as “complaints”. It seems to be a form of medical reductionism, which means in a lot of the case the essence of our experiences as patients are missed out on. A doctor might see us and think “tired, belly hurts, can’t sleep, don’t like sports”…

We are then viewed by professionals and researchers as a collection of ‘complaints’ rather than the profound disability we experience. This framing makes it easier to psychologise or dismiss our condition.

I was emailing a researcher recently and asked them what they think the odds are we find a cure within the next 20 years. They said that isn’t extremely likely but a treatment that alleviates most symptoms by around 50% is definitely a possibility. But to me, someone who can’t talk, is bedridden, 50% more or less symptoms is obviously a change, but it doesn’t fundamentally change much, at the end of the day, I’m still stuck in my bed isolated from the world. A treatment that can improve functional capacity by 50%, even if my symptoms stay the same, now that would be a profound lifechanger.

Why are we focused on the symptoms, and not the disability? (and the phenomenon of PEM, which seems to be the driving factor behind the disability)…

 

[alex3619]

In assessing disability using checklists for other diseases we often fall short. That is, in my opinion, a problem with how disability is assessed. So it becomes easy for the disability to be dismissed. This affects both medical bureaucracy and the medical practitioners as a whole, will follow on effects to research.

Let me explain further. Often each line item, based on personal experience, is based on whether or not you can do something. Not how often, or how hard it is, though frequency sometimes gets considered. PEM changes everything. They do not take it into account. They do not take many symptoms into account either, though some are disabling in their own right. We often have a choice of doing one thing OR another, but this would be assessed in many cases as you were able to do both.

These are my current thoughts, but I am interested in finding out if there is any published research on this area that might shine a light on it.

Personally I was assessed as disabled based on my least disabling problem, because they could at least understand it.

 

[Trish]

I'm with you on this, @Yann04. I don't think I feel sicker in terms of severity of symptoms now that I'm housebound and spend a large proportion of my day lying down, compared to when mild and able to work part time. The big difference is in how much activity I can do without triggering PEM. For me, the only symptom that has got worse is orthostatic intolerance. I think my muscle pain is generally less, since its severity is directly related to how much I use each muscle.

This is why I think the FUNCAP functional capacity questionnaire is so much more valuable than a symptom questionnaire in assessing illness severity.

 

[Keela Too]

Good point @Yann04

I have more function now than I did, but also more general aches and grumbles.

When I was more ill, I had to be SO cautious. I couldn’t risk any symptoms of this level, because the aftermath was days of increased symptoms, greatly reduced function, and often a further long-term decline in my abilities.

As things are for me now, I still need to rest up often, but I can allow myself to do more and feel more aches with much less risk of relapse.

I have more functional capacity, but not necessarily fewer symptoms.

(Edit - After an astute comment below, I’ll rephrase the above to: I am less physically disabled now, but I don’t necessarily have fewer symptoms.)

PS I am still much more cautious about my activities, than I would be if I hadn’t got ME. So this isn’t me throwing caution to the wind, it’s just I can now allow myself to do a few more things. It’s all about assessing the risk, and also about the mitigations put in place to protect myself.

 

[Kitty]

Why are we focused on the symptoms, and not the disability?

I wonder how much the biopsychosocial model has contributed to this in ME/CFS.

There's no incentive at all for those researchers to have measured disability because of the fact that even people who scored higher post-treatment were not returning to their normal lives. It would completely undermine their model.

 

[SNT Gatchaman]

If a person is pacing well then the severity of baseline symptoms might well be mostly mild, modest or even minimal. I find there is a wandering baseline so some days are certainly less kind - perhaps that is a milder form of "a-bit-of-PEM". But with PEM proper those symptoms increase in number and severity by orders of magnitude.

It's very difficult to have to prepare beforehand and recover afterwards in order to see a doctor who will then see you at your best - all the while trying to explain that you are disabled by your illness.

Humans generally seem very bad at recognising delayed effects and assessing risk (see enthusiasm for lotteries vs fear of commercial flights, also climate change!). Doctors would have to overcome this and their specific BPS training and societal and collegially-reinforced biases against chronic illness (cf chronic disease). It's unsurprising that finding a doctor who gets it is uncommon.

 

[rvallee]

Good and important question, especially given how the entire evidence base for chronic illness is based on alleged improvements of unrelated secondary symptoms centered on mental health. But as noted in other comments, they never improve functioning, so it would completely undermine, well, everything.

It seems mostly to be because of a combination of the mental health exemption, medicine still has no idea how to deal with mental illness, has made no progress in being able to tell apart from other conditions without a test telling them it's not that specific condition, and this has been abused to create giant loopholes into which we were cast out.

You are absolutely right that even 50% improvement in my symptoms would mean absolutely nothing to me if I can't do anything more as a result, although of course they go hand in hand so it's hard to conceive how this would work. But functional capacity can be conceptually cheated. I don't think it actually happens much, but humans in general have an obsession with being taken advantage of, and it's especially heightened in medicine. The need not to be taken for a fool is much higher than the need not to miss a diagnosis. Although that would be disputed, the fact that millions of lives are thrown away entirely because of this shows otherwise.

This is very important because we have examples like PACE, where the increase in walking distance was trivial and no one returned to employment. No one seems bothered by that, it's still asserted that CBT and GET treat fatigue completely. Even though the data don't even support that at all. There is zero improvement in functioning, so they simply discard that and focus on reporting of symptoms, which they openly try to manipulate.

So I think it all comes back to the obsession with being cheated. It's the same reason why mental health care is so poor. They almost never achieve good results, so that has made failure to improve functioning normal and just the way it is, with zero incentive to improve or change anything. But there it's usually the reverse, so this really places us in that odd void where nothing matters. Usually the focus in mental health care is to reframe symptoms so that they interfere less with functioning. But for us since they can do neither, it just becomes this incompetent jumble where nothing happens.

But I think this is something we can and should emphasize. How symptoms really don't matter if they don't affect functioning. So everything should be about increasing functioning, and there hasn't been a single trial that has shown that, as opposed to a few where secondary analysis can be framed as having improved symptoms.

We find the exact same in LC. If only reality mattered. But psychosomatic ideology has carved out this space where we get the worse of medical care and of mental health care, which for all the tropes about biopsychosocial this and that remain fully separated, all entirely by the lack of reliable testing.

But this is all so odd because technically functioning is what rehabilitation is all about. They never achieve that, but it just doesn't matter because it's all made-up. So really in the end we're stuck because nothing matters when it comes to us. Reality just doesn't factor in, even the special bubble where mental illness mostly fails.

 

[alex3619]

I don't think I feel sicker in terms of severity of symptoms now that I'm housebound and spend a large proportion of my day lying down, compared to when mild and able to work part time.

Once I fully implemented pacing I felt much better at a higher level of disability than when I was working part time or studying at university. Symptoms relate not just to the severity of illness for me, but how it is managed. Symptoms are worse when things are mismanaged. Learning to adapt and manage things is not easy, and takes a long time, but it pays off in the end.

 

[dave30th]

Limitations in function are obviously incredibly important. But it's also a good idea to be careful when using the term "functional" because of its parallel use in the construction "functional disorder"--which, as we know, basically is an updated term for "psychosomatic" or "non-organic." Just something to pay attention to and make sure it's clear from the context what is meant by "functional."

 

[Kitty]

Yes, and it's probably not needed. 'We see a focus on symptoms rather than disability.'

 

[Jonathan Edwards]

I am a bit puzzled by this. If loss of function/disability is blamed on PEM and PEM is the name for a set of symptoms, aren't we back to the central problem being symptoms?

My worry has been that researchers have not focussed enough on symptoms and tended to think they are trying to explain loss of muscle power or supply of ATP-derived energy or blood volume ('POTS') or 'neuroinflammation' or 'gastroparesis' when we have little evidence for these being the problem. What is different about ME/CFS, and so what I think should be homed in on, is a set of symptoms that aren't quite like those found when these physiological changes are known to occur in other conditions are seem likely to be due to something we have not yet pinned down at all.

 

[Yann04]

I am a bit puzzled by this. If loss of function/disability is blamed on PEM and PEM is the name for a set of symptoms, aren't we back to the central problem being symptoms?

To me, PEM is far from only a worsening of symptoms.

PEM feels like a worsening of the underlying disease, and importantly, when in PEM, my threshold for triggering more PEM is lower. This lowering of the threshold is what’s keeping me from doing stuff I do when not in PEM, not the increased annoying symptoms.

PEM, and the fluctuation of how much it takes to trigger it, not my symptoms, or even the symptoms PEM itself causes, are the main factors in my functional capacity.

 

[Jonathan Edwards]

To me, PEM is far from only a worsening of symptoms.

But is a doctor and a scientist I do not understand that because 'PEM' is the name for an increase in symptoms over a certain time course. That is what the term means - otherwise known as post exertional symptom exacerbation.

We assume that PEM is due to some part of an underlying disease process but until we have some idea what that process is, it is not clear what 'worsening of the underlying disease' might mean. If someone with heart failure tries to climb a hill despite knowing they will get short of breath and ends up spitting froth and gasping for air that is not worsening of the underlying disease. The heart remains as bad as it was but no more so.

And until we have a clue to what the disease process is all we have to go on is the symptoms.

 

[Yann04]

But is a doctor and a scientist I do not understand that because 'PEM' is the name for an increase in symptoms over a certain time course. That is what the term means - otherwise known as post exertional symptom exacerbation.

And Chronic Fatigue syndrome was defined as long term unexplained fatigue 20 years ago. That doesn’t mean it was an accurate definition, or that it fully encompassed patient’s experiences.

And until we have a clue to what the disease process is all we have to go on is the symptoms.

But for example what I’m saying here is that me, and a lot of others I’ve talked to, our disability is more defined by the fluctuations in the threshold it takes to trigger PEM, than the symptoms PEM can lead too.

I would choose a medication that permanently increases that threshold by 10% over a medication that permanently improves my symptoms by 50%.

Similarly, like a few others have mentioned, my symptoms (except OI) aren’t any more severe now that I’m bedridden compared to when I was mild, it’s just my threshold for triggering PEM is so much lower.

 

[Keela Too]

Yes! The threshold for WORSENING of the whole shebang is the problem.

When at my worst, my disability ratchetted downwards with every attempt to try and do something.
Symptoms in the moment, or even in the PEM stage afterwards, was not what stopped me doing stuff.

It was the shocking lowering of my threshold for the damaging type of PEM that was so scary, and what stopped me from pushing.

After a certain drug treatment, my threshold lept up. I followed that and tried more. My threshold remains at this higher level, but still very much exists and I have HUGE respect for it!

I do not want to be back in a situation where the ratchetting down starts again.

Psyches might say I’m afraid to exert myself. They might say I’m scared of a few symptoms. That’s not the case. I’m cautious because I want to preserve a reasonable future for myself!

 

[Trish]

But is a doctor and a scientist I do not understand that because 'PEM' is the name for an increase in symptoms over a certain time course. That is what the term means - otherwise known as post exertional symptom exacerbation.

We assume that PEM is due to some part of an underlying disease process but until we have some idea what that process is, it is not clear what 'worsening of the underlying disease' might mean. If someone with heart failure tries to climb a hill despite knowing they will get short of breath and ends up spitting froth and gasping for air that is not worsening of the underlying disease. The heart remains as bad as it was but no more so.

And until we have a clue to what the disease process is all we have to go on is the symptoms.

Maybe muddling up different things here.
From a pwME's perspective, of course symptoms are central to our experience, but it is the pattern of how exertion affects the severity of symptoms and consequent ability to function that matters in terms of impact on our lives. So assessing severity of illness needs to be based on capacity to function, not just on how bad the symptoms are.

 

[Kitty]

My worry has been that researchers have not focussed enough on symptoms and tended to think they are trying to explain loss of muscle power or supply of ATP-derived energy or blood volume ('POTS') or 'neuroinflammation' or 'gastroparesis' when we have little evidence for these being the problem.

That's true, but maybe what's being highlighted is a slightly different thing. The trials we've seen so far (including the BPS ones) have focused on reporting slight improvements in individual symptoms—claimed them as treatments in some cases—when they have little or no effect on the overall level of disability.

Of course it's worthwhile to find ways of relieving headaches or GI symptoms, quality of life is important. But it's not a treatment for ME/CFS, and it doesn't mean someone can now work or study or take part in family life. Perhaps trial outcomes should look more at how much people can do after treatment, rather than how their experience of one or two aspects of their illness has changed.

 

[Mij]

I am a bit puzzled by this. If loss of function/disability is blamed on PEM and PEM is the name for a set of symptoms, aren't we back to the central problem being symptoms?

I describe delayed PEM as loss of function.

The Disability Tax Credit eligibility in Canada is based on loss of function and how it affects our day to day life. It is not based on symptoms or diagnosis It's tricky putting it in writing when I have to renew every 5 years.

 

[Creekside]

I see the focus on symptoms as correct, since treating symptoms also solves the disability caused by those symptoms, while treating disabilities without treating the causative symptoms is less helpful and may result in further worsening. Crutches may "treat" the disability of a broken leg, but I'd really, really rather have the break treated properly.

 

[Jonathan Edwards]

And Chronic Fatigue syndrome was defined as long term unexplained fatigue 20 years ago. That doesn’t mean it was an accurate definition, or that it fully encompassed patient’s experiences.

That seems to me irrelevant. If a term is defined as meaning something then that is what it means. PEM may be inadequately described as malaise, fatigue or exhaustion or whatever but the term means an increase in symptoms.

our disability is more defined by the fluctuations in the threshold it takes to trigger PEM, than the symptoms PEM can lead too.

I am afraid I just don't follow that. The problem is the symptoms, surely. The threshold may change and one of the things I have tried to emphasise is that we need to get clear what the time course and fluctuation pattern is, but if it isn't worsening of symptoms that is responsible for disability I m unclear what it is.

I would choose a medication that permanently increases that threshold by 10% over a medication that permanently improves my symptoms by 50%.

But raising a threshold for getting symptoms is surely a reduction of symptoms for a similar level of activity. I don't see a way of disentangling those numbers. I agree that functional ability is likely to be a better outcome measure than symptom scores in trials but that is a different issue.