Member comments wanted: Second section (Who the guideline is for) of the NICE ME/CFS guidelines draft scope

I am not sure how less impaired is related to diagnostic criteria. A mild or moderate ME patient is less impaired than a severe one, but they are all ME patients.

If you are suggesting less impaired means not having ME, then i can begin to follow, but the answer to patient manipulation is not better diagnostic criteria, the answer is the study is flawed and uninterpretable.

 

I agree with you on this - like Cochrane, the AHRQ review also failed to properly consider the serious problems with these studies - what the IOM report referred to as the lack of internal validity of the studies. That is an essential point that of course NICE must understand. But IOM's additional point is that because of the definitional issues, these studies also lack external validity - that is, they do not represent people with M.E. Same argument as the 2016 AHRQ evidence review

I think it's a reasonable and fairly basic expectation that creators of evidence-based guidance should pay attention to both the internal and the external validity of the evidence examined. Perfect studies applied to the wrong patient population are still bad medicine. And I'd think using both bolsters the arguments based on the poor quality of these studies.

We have both problems. Treatment recommendations are being made for people who experience PEM based on people who do not experience PEM. Whether one accepts the CPET data or not, this systemic intolerance to exertion is significant enough that the IOM based its recommended name on it and researchers everywhere are using exertion challenges in studies to provoke the disease so they can study it.

 

There are good reasons to think that many of the patients the CBT/GET proponents are working with do experience PEM. This is apparent from the CBT/GET proponents having written much about "setbacks" and "boom and bust behaviour". In my eyes these refer to PEM. The patients they are working with are most likely on the milder end of the range of severity for various reasons.

Misdiagnosis does occur but I do not think to such a degree that treatment recommendations for one patient populations are based on observations of a totally different patient population. The pediatric diagnostic criteria might be an exception because they are extremely broad.

 

The trouble is I don't think we know that. Treatment recommendations have been made based on poorly interpreted data on a cohort, an unknown proportion of whom had significant PEM. I agree there are several reasons, including doubts about sampling and breadth of applicability (I think what you mean by external validity), that make PACE and related studies unhelpful. But the question is not the definitions used in past or future research studies but the range of clinical presentation that reasonably goes under this guideline.

I know that Drs Nacul and Lacerda are in favour of a simple PEM-based definition of ME and it sounds very sensible to me. But we do not yet know that it defines any unique process and some people at some stages of the illness do not appear to have PEM. I think to be of practical use to doctors the guideline needs to provide some sort of pathway for people without PEM.

I applaud the IOM for sticking its neck out and identifying exertion intolerance as the key feature of the ME syndrome. I do have doubts about the words systemic and disease though. I do not know what systemic means in this context. I had assumed it was intended to be read as 'a systemic disease with exertion intolerance' rather than 'systemic intolerance'.

 

If PEM is not one of the key hallmarks of the condition, then what is the range of clinical presentation that will be covered by the new NICE guidelines for ME/CFS diagnosis and management? Others may feel differently but IMO, the range of clinical presentation should not encompass anyone with medically unexplained chronic fatigue as the medical rationale for such a construct is weak to non-existent.

I appreciate the need for clinical guidance for patients who do not experience PEM. We have that issue in the US with Fukuda CFS patients who do not meet the IOM criteria. They need care also and cant be thrown into the MUS pit. But guidance for patients who do experience PEM is not necessarily appropriate for patients who do not. IMO, using one guidance for both will not help anyone.

 

As a doctor (and a scientist) I do not really understand that. The medical rationale for the construct of medically unexplained chronic fatigue is that there are quite a few people with medically unexplained chronic fatigue - an undeniable fact! Clinical medicine is about taking real people, seeing what their problems are and trying to devise pathways based on those problems. If you know the cause of the problem that can help categorise but for either ME or for MUCF we don't.

Again I would emphasise that clinical care does not in general take any note of what sets of research diagnostic criteria people fall under. I don't think there is any need to assume that NICE will produce one pathway for everyone. In fact one of the things that worries me is that they will suggest all sorts of options including CBT and GET 'if they suit you'. My feeling is that it would be sensible to put in that people with PEM should probably be advised to be particularly cautious about trying to ramp up exertion because people routinely report that being a problem. But that does not need any reference to any research criteria.

 

I was referring to what range of clinical presentation the new ME/CFS NICE guidelines are intended to cover. They are not intended to encompass all people with medically unexplained chronic fatigue, are they?

 

I suspect they will be the only guidelines available for GPs to turn to in that situation so they have to cope with that. Either the GP or a specialist to whom they are referred can at any stage decide whether ME or CFS is a useful diagnosis for the patient or not. That may influence how much further investigation is warranted or what sort of prognosis is given. Similarly, a GP would probably want to consult the guidelines for rheumatoid arthritis when faced with any patient with what appears to be some form of inflammatory arthritis.

In general specialists never bother to look at guidelines because they are supposed to keep themselves informed of recent developments. Specialists may have to take note of guidelines if they restrict what they are allowed to prescribe, even if it is based on recent evidence, but we are not really in that situation for ME/CFS.

 

I am admittedly unfamiliar with how British GPs use guidelines. But that sounds concerning as it suggests that ME/CFS will continue to be equated to and subsumed in a bin of medically unexplained fatigue. I would have expected clinical guidance to make it clear that ME/CFS is no more a part of that bucket than multiple sclerosis or other diseases which also cause fatigue and for which there are separate NICE guidelines.

 

Presumably if there is no evidence of real benefit, and no real understanding of illness definition, but at the same time strong indications that some people within the broad definition are likely being harmed by a treatment, it doesn't really matter that you don't know which sub-group(s) are prone to harm, the case is still strong to not administer GET.

 

The fatigue of MS is explained by the existence of a clearly defined pathology - central demyelination. ME is not explained in that way and so strictly speaking is a form of medically unexplained fatigue. I agree that it looks as if it is a specific physiological problem but as yet we do not have an explanation. I am not sure talking about buckets or bins when referring to groups of ill people helps. People who have disabling fatigue but do not happen to fit a defined syndrome deserve as much care as anyone else surely? Fatigue may not be the best word for people with ME but it may not be the best word for the other people either.

At a research level it is important to try to tease out syndromes that look as if they have different mechanisms, even if we do not yet know what they are. But in clinical care, one is always just trying to find the best options for an individual person and very often that does not depend much on diagnostic pigeonholes. It depends on what their problems are.

 

Yes I think we have to worry that some people who end up disabled and with PEM may be just as susceptible to long term ill effects of exertion at an early stage when they do not recognise PEM as those who start with PEM, if indeed there are long term ill effects.

 

Interesting. Because my wife, like so many with ME I think, has always been someone who pushes herself through any bugs she catches, and without being clairvoyant, and without having very savvy medical advice, would have no way of knowing 'this' bug is the one to not do that with, else you may tempt the devil. In fact thinking about this, my wife's natural instinct regarding pushing through a bug, is probably much akin to GET. Makes me wonder if she had not done that with that particular fateful bug, maybe life would be very different for her now.

So many people with ME seem to be the sort of characters who push through their troubles no matter what, a bit like GET presumes to formalise, I wonder if that is a common denominator for many who fall prey to ME? Maybe a form of GET (done unwittingly by many in their disease's embryonic phase) could in fact be the final straw that tips them from recovery over to ME. Could this be why more women get ME? Are mums of young children more prone, where they just have to keep going?

 

I agree that all people who do not fit a defined syndrome also need care. But I think it would be a problem if the NICE ME/CFS criteria were to be used for both people with ME and for people with other causes of chronic fatigue for which there is not yet a medical explanation. Especially when, while we don't have the exact explanation, IMO, there clearly is a medical explanation for ME.

 

It is also important to try and catch PEM and orthostatic intollerance early on in patients with unexplained fatigue because that can prevent unnecessary suffering and may improve the prognosis.

 

I doubt that insurance companies would demand that. They would risk handing the patient proof of disability on a silver platter.

 

The CCC and ICC do make a nod to the need to cover both groups of patients by having the possibility of an ME (or ME/CFS) diagnosis, atypical ME and idiopathic chronic fatigue by simply fulfilling more or less of the same set of criteria. So if you lack one or two of the secondary criteria, it's an atypical diagnosis. If you lack PEM or one of the major criteria, it's an idiopathic CF diagnosis ('suspected ME/CFS' might be more accurate/less contentious).

One of the Scottish reports (I can't remember the name) went further and suggested CCC guidelines for ME with a looser set of NICE-based CFS guidelines for those who don't fit the stricter criteria. Splitting the guidelines like that doesn't make sense to me. I also think they missed a trick, since CCC already includes the 'suspected' cases. They would just need one set of criteria instead of two.

It seems to me that stratifying patients would be very helpful, but also offering guidance for atypical or less well defined, 'suspected' patients is also helpful. Having two guidelines would be an issue, and I don't think many patients would actually prefer that in practice (there might be stigma associated with getting the 'wrong' diagnosis). Therefore, perhaps it needs to be one set of criteria with a qualifier or two to cover the outliers?

Does the draft scope already implicitly cover those people when it talks about 'those diagnosed with or suspected of having'? Or do we need something like the CCC diagnostic pathways: ME, atypical ME, idiopathic CF (all in one guideline)?

Maybe a strong, PEM-based criteria (IOM as a minimum) with a couple of lines to the effect that atypical cases may lack one or two of the secondary features; and that patients without the core feature of PEM, but for whom another diagnosis is not forthcoming, should continue to be monitored but treated immediately.

Or is it to be expected that GPs and clinicians will pragmatically label patients who don't fit the full profile as 'atypical' or 'suspected' cases anyway, without us labouring the point? In which case, stronger criteria might not exclude those patients anyway.

 

Pretty sure Charles Shepherd spoke of this.