Lori Chapo-Kroger, PANDORA Org (Video )___________________
PANDORA Org submitted two written comments to the IOM committee for the public meeting. 1) The Needs of the Severely Ill has pictures to show how people suffer with this illness, and 2) Critique of the NICE Guidelines. (Transcripts HERE .)
We are all concerned that this process will further set back patient care, and we are concerned that history will repeat itself and patients will end up in a worse position. In the real world, ME/CFS is used as a wastebasket diagnosis. It’s time to take us out of the wastebasket.
Fatigue is a symptom, not an illness. Fatigue is the 7th most common symptom reported to doctors. Fatigue is also experienced by healthy people, and it can result from virtually every physical or psychological illness. These conditions are not under one big “chronic fatigue umbrella,” because fatigue is a symptom of so many diseases.
The main problem in a clinical setting of a fatigue-based definition is that doctors confuse chronic fatigue with chronic fatigue syndrome. They diagnose patients who have primary psychiatric disorders with CFS, and are not educated in illness severity. They prescribe physical therapy and exercise that worsen patient outcomes. They don’t have specialists to send patients to, and they fail to diagnose the disease.
There are some case definitions that are very broad, where the only criteria is that patients have six months of fatigue and a few other symptoms, and others, like the Canadian Consensus Criteria that are concise. But the multiple definitions and the overly broad definitions are causing clinician and researcher confusion.
When looking at research in your study we recommend that you reject all research that focuses on, or only requires, chronic fatigue. Those studies do not inform you on our illness. They inform you on a symptom of many diseases.
Some of you may think that a broad definition would be better for patients, because a more focused definition would limit treatment. This isn’t true for ME/CFS because some of the treatments that are prescribed for idiopathic fatigue are harmful for patients. For example, someone who has depression should be exercising more to release endorphins, but someone with ME/CFS will need to be careful to not exacerbate symptoms by exercising.
We need you to develop a definition that distinguishes between primary depression, idiopathic fatigue, and other organic diseases. Why? Because we want the right treatment. We need a definition narrower than Fukuda and Oxford to eliminate idiopathic fatigue and primary depression, but balanced enough to include patients that represent a proper cohort.
The case definition drives correct diagnosis, drug trials, classification, disability assessment, research, and will lead to a proper name.
Mary M. Schweitzer, Ph.D., Wisconsin ME/CFS Association, Inc. ( Video ) ( Transcript )
Key message: This is a national public health catastrophe. We need to address it with urgency, not by going back to the drawing board 30 years ago.
Thank you for allowing the Wisconsin ME/CFS Association time to speak; Pat Fero is not here but we worked on this presentation together.
We have known about Myalgic Encephalomyelitis since 1934 (when it was called atypical polio); it was classified as a neurological illness by WHO in 1969.
In the mid-1980s, a series of mysterious cluster outbreaks of the disease occurred around the nation. At first, because many cases seemed to start with a bout of EBV, they called it “Chronic Epstein-Barr Virus,” or CEBV. But common thinking at the time was that you had an acute case of a virus, and then you were immune to it. Barring something like AIDS, there could be no chronic EBV. NIH decided this had nothing to do with the immune system - and that it had nothing to do with EBV.
NIAID's EBV specialist, Stephen Straus, who coined the name CFS in 1986, decided that the disease was somatic (the physical expression of a psychiatric problem) – the result of depression and/or stress. For the next three decades, what little funding NIH allocated went to fatigue studies or studies of stress hormones. As for cluster outbreaks, it was decided they were outbreaks of friendly diagnoses.
At CDC, the first demographic efforts came up with a figure of 10-50,000 patients with CFS, all white upper middle class women. Critics noted that the method CDC used was to ask physicians for information about patients they saw with CFS, which heavily tilted the data set towards those with the means and determination to find someone who could diagnose and treat them.
In 1999, Leonard Jason and a team at DePaul estimated that roughly 800,000 American adults probably had the disease, and the disease affected all income groups and all ethnicities. This estimate has been in use ever since – today, the DePaul estimate would put the number of patients closer to 1.3 million.
In 2003, Canada adopted its version of ICD-10, which included CFS, along with M.E., in neurology. A committee was convened of clinician experts, including several from the US. The result is called the Canadian Consensus Criteria and it does an admirable job of capturing the complexity of this illness.
In 2004, CFSAC recommended to the Secretary of HHS that the US adopt the Canadian Consensus Criteria - and that's when we found out that money allocated to CDC to study young people had been misused.
The money had been spent on closed annual meetings at a resort. According to Dr. Reeves, they had created a new definition for CFS (the “New International Definition”). Comparing the Canadian criteria with Reeves' questionnaires, Jason found that Reeves lost the bottom 30% of patients, while inappropriately including patients with primary mood disorders
Researchers never used the Reeves questionnaires. The funds and the time spent were wasted.
M.E. experts desperately need funding to replicate and further new research on exercise physiology, immunology, virology, genomics, and intricate metabolic research. Please do not repeat the errors of the past – do not waste money on something that researchers do not want and will not use.
A study published in PLoS ONE just over a week ago showed that 3/4 of CFS patients had a deficient EBV-specific B and T-cell response. It appears the dismissal of EBV as having a role in the disease was premature.
Recent research has also shown that 80% or more of CFS patients suffer from chronic infections of CMV, HHV-6, and/or HHV-7. There are new studies on Coxsackie B.
Patients have been found to have abnormal natural killer cell function, abnormal 37kDa Rnase-L, and abnormal cytokine functions. They have abnormal SPECT scans and CPET tests
With so many ongoing research projects, is it any wonder that 50 experts signed a letter asking HHS not to spend one million on this study? If you create a new, more heterogeneous definition and name - let's say, "Multi-system disorder," will applications for NIH research funds and NDA applications require that the researcher meet the new definition? That would set research back terribly.
Now that scientists are again making great breakthroughs, we do not need to descend yet again into a name that implies this is a poorly understood and vague illness having something to do with pain, fatigue, and sleep. We did not need the detour into CFS, and we do not now need a new detour into something like Multi-symptom Disorder.
We need CDC to come out against efforts to portray this illness as psychosomatic, or“factitious illness,” or “factitious illness by proxy,” a euphemism for the discredited Munchausen’s Syndrome by Proxy.” We need CDC to stop suggesting exercise programs.
The government needs to work WITH the experts to find ways to use the biomarkers that have been found, to explain to the world the scientific discoveries that have been made, to fund large studies to confirm or deny the smaller ones. M.E. is NOT a mysterious disease. There is a great deal that is known about it. Listen to the experts.
This is a national public health catastrophe. We need to address it with urgency, not by going back to the drawing board 30 years ago.
Carol Head, CFIDS Association of America, President and CEO of the CFIDS Association of America ( Video ) ( Transcript )
Key message: Patients wait for years, and see many doctors, before they obtain a diagnosis. We believe that the Canadian Consensus Criteria can be optimized as a clinical case definition by applying a standardized methodology, validation of criteria, and nationwide dissemination to health professionals.
Our involvement in this IOM process stems from our desire to inform the regulatory framework and to accelerate approval of ME/CFS therapies. The development of safe and effective treatments for ME/CFS requires strengthened, uniformly-accepted criteria that can be used consistently by researchers, clinicians and patients. The lack of uniformly-accepted clinical diagnostic criteria is one of many reasons for the slow progress against this illness.
The FDA has stated that, “When there is confusion, lack of consensus and no progress, go back the Core.” The “core” regulatory framework for any disease is: core signs, symptoms or decreases in specific functioning. The FDA recognizes that for ME/CFS, we are still at the very beginning of understanding the core.
We applaud HHS’s effort to address this critically important issue. And at the same time, we anticipate that your work will be extremely difficult, despite your best efforts, as the available research is more limited than any of us would want.
Despite disagreement about the best way forward, we all acknowledge the need for evidence-based, broadly-accepted clinical and research tools that can accurately include or identify all subsets of the heterogeneous group that presents under any of the case definitions of ME/CFS. We believe that the Canadian Consensus Criteria can be optimized as a clinical case definition by applying a standardized methodology, validation of criteria, and nationwide dissemination to health professionals.
This month, the CFIDS Association conducted a survey to understand the patients’ journey with ME/CFS. Of the 256 people who responded, 88% have been diagnosed with ME/CFS by a physician. 32% indicated it took 1 year or less to get a diagnosis, while 36% said it took between 1-5 years, 21% stated it took 5-10 years and nearly 12% waited more than 10 years to be diagnosed. This is a desperately long time to live with pain and impairment, without validation.
Further, the longer it takes to get a diagnosis, the worse a patient gets and becomes more difficult to treat. One of this panel’s charges – to get good diagnostic criteria into the hands of all physicians - is imperative for faster diagnosis and, therefore, better care.
Over and over again, patients told us stories of delayed diagnosis, lack of treatment, a need to educate the doctor, increased disability and even hostility due to physician lack of knowledge and empathy. Patients spoke of the unfortunate ignorance of some in the medical community.
This panel has an opportunity to rewrite that story.
(Read the full survey results HERE .)
And while it’s imperative to develop and disseminate consistent diagnostic criteria, we know that time has not stood still. The few clinicians who specialize in ME/CFS have developed solid intuition and are now treating a few patients to mitigate their symptoms in some cases. This is far from a cure and the situation is not ideal, but treatment is occurring and should not be ignored. Wanting to better understand ME/CFS clinicians’ intuition, in 2012 we conducted a survey asking 25 physicians – all ME/CFS experts – how they treated their patients’ symptoms. [Ms. Head showed a chart of some of the CFIDS Association’s survey results.]
And going even further, good clinical diagnostic criteria will lead to biomarker discovery. [Ms. Head showed a slide of blood samples from the SolveCFS BioBank; the samples were selected using the Canadian Consensus Criteria. The horizontal axis showed 100 different genes and the vertical axis showed whether the sample was from an ME/CFS patient or a control. The majority of ME/CFS patients above the line were distinct from the majority of the controls below. It’s noteworthy that these samples came from patients being cared for by expert ME/CFS physicians – who use current clinical definitions and diagnostic criteria – again demonstrating that clinical diagnostic criteria is possible for ME/CFS.]
The credibility and authority of this IOM committee is important to making ME/CFS widely recognized and diagnosed throughout our nation’s medical community. And that will help the one million Americans who struggle with this serious illness. The success of this committee is of great importance; you have an unprecedented opportunity in the history of ME/CFS.
Lily Chu: I wondered if you have any information about duration of illness, and if people who have been sick for a longer period of time had more difficulty getting diagnosed in the past than in recent times.
Ms. Head: I am happy to provide you with the full results of the study, but I don't think it will answer the question you asked. The survey is not longitudinal and we did not explore how long an individual has had the illness.
Pat LaRosa, New Jersey Chronic Fatigue Syndrome Association, Inc. ( Video ) ( Transcript )
Key message: We urge you to adopt the name Myalgic Encephalomyelitis (ME) - a name that is appropriate to the severity of the disease. The name CFS discourages proper coding, and creates numerous obstacles for patients.
Outside the US, the name Myalgic Encephalomyelitis (ME) is accepted internationally, including the World Health Organization (WHO.) In recent years, ME has been accepted by US government agencies, using ME/CFS as the name. Some references might be needed for a time to redirect people to ME, but it is now time to make the change to the single factual name.
In 2011, the name “Chronic Fatigue Syndrome” was rejected by the international panel that wrote Myalgic Encephalomyelitis: International Consensus Criteria. In this document, ME is declared the appropriate name based on "research and clinical experience that strongly points to widespread inflammation and multisystemic neuropathology." It further states, “Using ‘fatigue’ as a name of a disease gives it exclusive emphasis and has been the most confusing and misused criterion.” No other disease adds fatigue to its name.
We urge you to adopt the name Myalgic Encephalomyelitis (ME) - a name that is appropriate to the severity of the disease.
The CDC defined and named CFS in 1988. At that time, the ICD-9 included ME under “Diseases of the Brain.” There was no listing for CFS until 1991, when it was added under “Symptoms and Signs/Malaise and Fatigue.”
In the ICD-10-CM, there two places that ME/CFS might be classified.
G93.3 - acknowledges neurological pathologies, viral triggers and the relationship of ME, CFS and PVFS. Studies have shown differences between brains of people with CFS, healthy controls and those with psychological disorders. These brain changes justify ME/CFS as a disease of the neurological system. This G code enables patients to receive proper diagnosis, treatment, and disability benefits.
Unfortunately, it is not very well known to physicians and a patient may be coded as having CFS in the R code, instead of ME/CFS in the G code.
The ICD-10-CM is coordinated with the Centers for Medicare and Medicaid Services (CMS) and electronic record keeping. Improper diagnosis can negatively affect the response of doctors reviewing patients' records.
Social Security disability programs use the name “CFS.” Many private long-term disability (LTD) providers follow the SS guidelines and also use “CFS.” Some LTD plans have two-year limits for "mental impairment." A physician using the R code for the vague illness of malaise and fatigue may possibly create an obstacle to obtaining LTD benefits. A diagnosis of ME under the G code would be a definite improvement. The coding issue circles around to the name issue.
These aspects, “name” and “coding,” are of major importance. Please consider these comments as you proceed.
Charmian Proskauer, Massachusetts CFIDS/ME & FM Association, president of the Massachusetts CFIDS/ME & FM Association ( Video ) ( Transcript )
Key message: A separate clinical definition for pediatric ME/CFS has been developed and should be added to the list of clinical definitions that you consider in your study.
I am here to speak on behalf of children and adolescents with this illness.
Children and adolescents are an important group to consider separately, not merely as a “sub-group” of the adult illness.
ME/CFS is the most frequent cause of prolonged absence from school, and it is this prolonged absence that often leads school officials down the wrong path of falsely labeling ill children with “school phobia” or taking the parents to court for Medical Child Abuse. Children with ME/CFS want to go to school — and will tell you that if you ask them!
The adult definition is not appropriate for children and youth, as the initial presentation of symptoms may be quite different from that of adults. Also it may not be appropriate to ask an ill child to wait until the symptoms have persisted for six months (most of a school year) before receiving a diagnosis which will allow helpful management and treatments to be put in place.
While the onset, symptoms and course of the illness in youth can be quite different from that in adults, as with adults the symptoms vary in nature and intensity on any given day. This variability can cause providers and others uninformed about the illness to believe the symptoms are psychological.
Also as with adults, the illness is usually prolonged, lasting from several years to 10 or more. When a child changes schools, often the process of educating school officials has to start all over again.
The range of issues needing to be dealt with is also different — important aspects for a child include educational needs and social development as well as physical health. Addressing these issues involves the school, the family, and the community, as well as providers of health care.
Families with a chronically ill child already face many challenges. Caring for an ill child who does not have a recognized diagnosis, or with a diagnosis that family, friends, and school officials do not understand, is especially difficult. Without a diagnosis, the more severely ill a child is, the more likely the family will be under pressure from the school and the threat of legal action against them.
Pediatricians, at least in our state, have little knowledge of ME/CFS. When a school nurse recognizes a child with symptoms suggestive of ME/CFS, it is usually very difficult or impossible to find a pediatrician who can make the diagnosis which would allow the child to receive needed educational accommodations and begin appropriate treatment. Lacking a correct diagnosis, there is a significant risk, especially in the case of a severely ill child, that an incorrect diagnosis of Medical Child Abuse or Munchausen Syndrome by Proxy may be given, and the situation may escalate to the point where the child could be removed from the home or legally required to undergo an inappropriate treatment.
On the positive side, outcomes for youth, if good information, treatments, and social and educational support are provided promptly, seem to be better than outcomes for adults. However it should be noted that these studies do not include the most severely ill children, so we do not know the outcomes for them.
Nancy Klimas: As someone who has dealt with a number of "Munchausen by Proxy" cases in my clinical practice, I can't underscore how devastating it is to a family to see their child literally seized from them. I had one child who was forced into a foster care situation where they did morning calisthenics before he was shipped to school, with devastating consequences.
Theodore Ganiats: I am intrigued by the idea of trying to diagnose children earlier. But whenever you start diagnosing earlier, you'll have some false diagnoses. Because, I'm .. obviously, if you take it to the extreme, and have it be only one day instead of six months, then you're going to have problems. If you wait six months you're going to have problems. So, the question is if you have any data, or know of any data, on length of time of symptoms, and.. uh.. how well that is correlated with a final true diagnosis. [Note: Ms. Proskauer mentioned the existing pediatric definition in both her written comments, as well as those made only a few minutes earlier in her presentation.]
Ms. Proskauer: The existing pediatric definition, which was published by Lenny Jason and colleagues, suggests a three-month waiting period.
Gabby Klein, Phoenix Rising (Video ) ( Transcript )
Key message: ME is an organic, complex, seriously disabling disease, which needs a definition at least as strict as the CCC or ICC. Myalgic Encephalomyelitis. (ME) should be the term used for the disease.
Thank you for the invitation to speak on behalf of Phoenix Rising. We are a non-profit patient-led organization which hosts the largest online forum for ME/CFS patients.
We have enlisted our members to comment on the question posed by the IOM in their study to recommend clinical diagnostic criteria for ME/CFS
“What is the most important aspect or information that this committee should consider throughout the course of the study?”
Phoenix Rising members have identified several points of focus
ME is a complex, severely disabling disease involving multiple systems in the body. It involves extreme muscle weakness, drastic loss of stamina, cognitive dysfunction and viral symptomatology along with neurological and endocrine dysfunction. Fatigue is only a small part and not necessarily the most prominent symptom.
ME needs a definition at least as tight as the CCC or ICC
Most of the experts treating and researching ME have endorsed and are currently using the Canadian Consensus Criteria (CCC). They have recognized that by using post exertional malaise (PEM) as a hallmark of the disease and mandating neurological and immune dysfunction, the CCC best captures the patients who are suffering from this particular disease.
Any new definition for ME must include PEM as a minimal prerequisite for the diagnosis of ME.
The CCC were created to distinguish ME patients from those diagnosed using broad CFS definitions such as the Oxford Criteria of 1991 and the Fukuda Criteria of 1994. These definitions selected many who suffered from vaguely defined idiopathic fatiguing illnesses. These broad definitions have impeded serious research into the complex disease and have held the disease hostage without a chance of effective recognition and advancement.
Studies on the disease have shown that there are testable biomarkers, such as the two-day cardio-pulmonary exercise testing (CPET), which show remarkable abnormalities in ME patients. The fact that PEM/PENE is a hallmark of the disease is no longer debatable. Immune dysfunction has been shown, with multiple studies uncovering defects in natural killer cells in ME patients. Neurological/cognitive dysfunction has been shown by abnormalities in cerebrospinal fluid and structural MRIs.
We therefore ask the panel that the population of severely ill and disabled ME patients should be separated out from the broad fatigue-based definitions, using a definition at least as 'strict' as the CCC or ICC.
ME is not a psychogenic somatoform illness
Terms previously used to describe the syndrome CFS, such as “depressive mood”, “deconditioning”, “somatoform”, “personality disorder”, “childhood abuse”, “hypochondria”, “laziness”, “malingering” or “unwellness” do not apply to the organic disease of ME.
Other illnesses such as Asthma, Stomach Ulcers, Multiple Sclerosis, and Inflammatory Bowel Disease were thought as ‘psychosomatic’ until a known and identifiable physical element was discovered.
Any research into ME as a psychological, psychogenic or functional disorder should be disregarded. Attempts to give a psychiatric or somatization explanation for our illness have utterly failed to explain the realities of the condition, and are incompatible with the details of its progression.
Myalgic Encephalomyelitis (ME) should be the term used for the disease
The term “Chronic Fatigue Syndrome” (“CFS”) is not appropriate for this disease. No disease should be characterized by a symptom shared by many healthy people. Patients with different illnesses and different clinical needs are mixed together under a single ‘CFS’ label. CFS as defined by Fukuda may include people suffering from depression and idiopathic fatiguing illnesses. This leads to confusion in clinical settings often leading to chronic neglect.
ME, as described by the CCC, has a distinct and definable nature. It best describes our members’ complex and specific symptoms of muscular and neurological dysfunctions.
We would like you to know that our members have expressed many concerns about this study, especially the fact that many members of the panel, as currently constituted, lack appropriate expertise in the treatment or diagnosis of this disease.
In addition, there is a large group of stakeholders, experts, advocates and patients who are calling for a cancellation of this study and the adoption of the CCC now. Their concerns are due to the fact that they believe that a new definition can come only from a panel of knowledgeable experts. Some have questioned the legality of the contract as well as the lack of transparency in the actions of HHS. These feelings have resulted in their boycotting these proceedings and choosing not to take part.
Please keep in mind that the recommendations that this study will produce will directly affect the lives of millions of patients worldwide. We hope that you will take the patients’ voice to heart and that you will continue to invite us to be part of the process.
Jennie Spotila, OccupyCFS ( Video ) ( Transcript courtesy ME/CFS Forums)
Key message: The definition of ME/CFS must be both accurate and precise.
You are facing an enormous challenge, the result of decades of inaccuracy and imprecision in the definition and diagnosis of our disease. I believe the one thing you must keep in mind throughout this study is to be as accurate and precise as you can in order to create sensitive and specific diagnostic criteria.
Multiple names and definitions have been used in the last 30 years, and you should go back as far as the 1950’s to examine the descriptions and definitions of ME. Each definition carries with it a rationale, an associated description of the disease, and a set of limitations. Prevalence rates vary because each definition draws a different circle around – or within – a patient population.
Another challenge is that there are no gold standard biomarkers for the heterogeneous Fukuda population. Despite that, we are very close to establishing one or more diagnostic markers, and a number of you have been responsible for that important research. But the breadth and weaknesses of the case definitions have been a huge obstacle to achieving this.
Finally, as you no doubt realize already, there are competing schools of thought on case definition. Does the mixed bag of definitions describe one disease or more than one disease? How do we identify a more homogenous cohort? What should we call it? Who is competent to diagnose it? We do not agree on the answers to those questions because there are no easy answers.
As in any controversial subject, there are potential pitfalls that could complicate your work.
First and foremost is the fatigue paradigm. Severe fatigue lasting longer than six months is an extremely common symptom experienced by 4-5% of the general population. One study of newly diagnosed MS patients found that nearly 30% had been diagnosed with severe fatigue or CFS in the three years prior to the MS diagnosis. Because it is based on fatigue, the Fukuda definition has been used as a wastebasket for people with unexplained fatigue, consigning them to medical purgatory when they may have more treatable conditions.
It might help to draw a comparison to chronic pain. While pain conditions are researched across diseases to identify common mechanisms and treatments, we do not define and diagnose them that way. We do not diagnose fibromyalgia, vulvodynia, and migraines as one disease that is subtyped based on where the pain is located in the body because chronic pain is simply too common a symptom. I believe the same is true for the fatigue paradigm. Severe fatigue is simply too common a problem to form the basis of an accurate and precise case definition, regardless of how you try to slice it into subtypes.
Second, it is imperative to recognize which definitions and exclusionary conditions were used in each research study. If you do not take this into account, you will not be able to sort through the evidence with any resulting clarity.
Third, I believe it would be a mistake to lose sight of the impact your report will have in the real world. As Lori and Pat have said, you will have an impact on research and clinical trials. You will have an impact on policy. You will have an impact on clinical care. The stakes are very high, but there is a solution.
Accurate and Precise
I believe it is possible to create diagnostic criteria that are both sensitive and specific for ME/CFS. To do so, you will need to be as accurate and precise as possible.
Start by setting aside the fatigue umbrella, because severe chronic fatigue is common to many diseases, and should not be used as the foundation of a precise case definition. Instead, focus on the core symptoms of disease. Across multiple studies and surveys, post-exertional malaise – not fatigue – has emerged as the key and most disabling feature of this disease. PEM is an exacerbation of multiple symptoms after mental or physical activity, and can be measured through both self-report instruments and objective biological tests. It is also notable for its use in distinguishing between people with ME/CFS and those with major depressive disorder and other illnesses with a fatigue component. Another core symptom identified in the research is cognitive impairment, particularly memory and concentration problems. Unrefreshing sleep and autonomic symptoms also rise to the top. There are many other symptoms as well, but your diagnostic criteria will be more meaningful if you focus on the core features.
Another approach that will help you succeed is to use frequency and severity thresholds, in addition to a list of symptoms, to identify a more precisely defined patient population. In one study, 34% of healthy controls reported at least 4 out of 8 Fukuda secondary symptoms. When higher cutoff thresholds for frequency and severity measures were used, that number dropped to 5%. If you combine a core symptom set with thresholds for frequency and severity of those symptoms, I believe you will be able to establish accurate diagnostic criteria that have high sensitivity and specificity.
Precision is the most important tool at your disposal, and yet it will not remove all ambiguity and uncertainty because there is so much we do not know about this disease. Three hundred years ago, cancer could only be diagnosed when it advanced to externally palpable tumors. The definition of cancer has evolved from the most severe and easily detected form of the disease to the sophisticated detection and subtyping methods of today. Precision based on what we know is the first step.
In summary, you face the enormous challenge of creating diagnostic criteria for a disease with conflicting case definitions, no gold standard biomarkers, and competing views about how to define the problem. You must avoid multiple pitfalls, including the high prevalence of the symptom of chronic fatigue in the general population and the effects of those competing case definitions on research results, and never lose sight of the very high stakes we face. But there is a way for you to overcome all of these challenges, and that is by being accurate and precise.
If you set aside the fatigue umbrella and focus on the core symptoms of this disease, if you establish frequency and severity threshold requirements, and if you recognize that your diagnostic criteria will be part of an iterative process of refinement, then I believe you can create diagnostic criteria that will advance clinical care and research, instead of putting us further behind: a definition that is sensitive and specific to ME/CFS.