From EMEA UK member Invest in ME Research's web site -


Guidelines - what they are

One of the basic problems with treatment of ME is the original diagnosis of the illness.

Invariably it is too late and the current environment in the UK means that diagnosis may cover a broad range of illnesses with similar symptoms which are brought together under one diagnosis - sometimes ME - sometimes CFS.

In order to establish correct and early diagnosis there needs to be a standard clinical diagnosis method used throughout the country.

This area is currently clouded with up to four sets of diagnostic criteria being available for use.

When a doctor or paediatrician gives a diagnosis of myalgic encephalomyelitis then they do this currently by exclusion of other illnesses and by means of basic blood tests.

Diagnostic guidelines are meant to be a means to assist in diagnosis.

Why they are important

ME in the UK has suffered from the lack of adoption of a clear clinical diagnostic tool, resulting in ME sufferers not being identified correctly.

Instead, ME has been confused with other conditions that have chronic fatigue as a symptom.

This obfuscation has lead to a psychiatric lobby being able to diagnose ME sufferers with "somatoform" disorders, such as "Faulty Illness Belief.".

If a diagnosis is given to a patient based on a different interpretation of an illness then the diagnosis may be flawed.

In an illness such as ME, where politics and prejudice have affected how research is funded in the UK, using flawed diagnostic criteria or even using different criteria means that it will be even more difficult to establish a proper baseline for treatment/cure.

IIMER Position

A common, workable set of standard guidelines - adopted by all clinicians and researchers throughout the world - is an objective of Invest in ME Research.

It is one of the fundamental issues which needs to be resolved in order for myalgic encephalomyelitis to be treated in the correct way.

Currently IiMER require any research we fund to use the Canadian Guidelines as a minimum and all members of the European ME Alliance (EMEA) have endorsed the Canadian Guidelines.

Guidelines for ME

Here are the more common guidelines which you may come across. To read more on these we have added some links where the discussion on the merits, or otherwise, of these criteria are discussed more fully.

Canadian Consensus Criteria (Carruthers et al.)

Clinical guidelines from 2003 which can also be used as a base for research criteria.

Findings from the study by Leonard A. Jason PhD (Comparing the Fukuda et al. Criteria and the Canadian Case Definition for Chronic Fatigue Syndrome) indicated that the Canadian criteria captured many of the cardiopulmonary and neurological abnormalities, which were not currently assessed by the Fukuda criteria.

The Canadian criteria also selected cases with 'less psychiatric co-morbidity, more physical functional impairment, and more fatigue/weakness, neuropsychiatric, and neurological symptoms' and individuals selected by these criteria were significantly different from psychiatric controls with CFS.

A link to a full description of the Canadian Guidelines is held in the Library - click here.

An additional 2005 overview document can be viewed via this link.

A hard copy of this booklet can be ordered from Invest in ME Research. Invest in ME Research are the UK distributors for the current Canadian Consensus Criteria Guidelines and welcome these guidelines.
We have for a long time stated that we support an evolutionary development and improvement of the Canadian Guidelines.

Myalgic Encephalomyelitis: International Consensus Criteria 2011 (Carruthers et al.)

Another set of guidelines based on the 2003 Canadian Consensus Criteria and aimed at further defining myalgia encephalomyelitis has been was published in 2011.
The authors discuss the clinical application of their criteria, as well as paediatric considerations and research applications.
The authors conclude that they -
"believe the International Consensus Criteria will help clarify the unique signature of ME"
and they state unambiguously that "individuals meeting the International Consensus Criteria have myalgic encephalomyelitis and should be removed from the Reeves empirical criteria and the National Institute for (Health and) Clinical Excellence (NICE) criteria for chronic fatigue syndrome".


IOM guidelines

In 2015, the Institute of Medicine (IOM), now the National Academy of Medicine (NAM), published a report on ME/CFS called "Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness." The IOM committee summed up the evidence base and proposed simplified rdiagnostic criteria based on inclusion of core symptoms (A substantial reduction or impairment in the ability to engage in pre-illness levels of activity, Post-exertional malaise (PEM), Unrefreshing sleep and either Cognitive impairment or Orthostatic intolerance).

They state that "ME/CFS is a serious, chronic, complex, systemic disease that often can profoundly affect the lives of patients."

The report also suggested a new name SEID (Systemic Exertion Intolerance Disease) which has not received worldwide acceptance.

The report made it clear that the Oxford guidelines (often used by UK psychiatrists) should no longer be used to define ME/CFS.

The IOM review of all current guidelines

Fukuda Case Definition for CFS (1994)

This case definition has been the most widely used definition in ME/CFS research, and it has also been used for clinical evaluation of patients.
However, in recent years researchers and clinicians have started using the Canadian Consensus Criteria instead as the Fukuda Case Definition does not require the hallmark symptom of post-exertional malaise.
Patients only need to have any four symptoms from a list of eight ( substantial impairment in short-term memory or concentration; sore throat; tender lymph nodes; muscle pain; multi-joint pain without swelling or redness; headaches of a new type, pattern, or severity; unrefreshing sleep; and post-exertional malaise lasting more than 24 hours).

See also -

NICE Guidelines

NICE published a set of guidelines for CFS/ME in 2007.

They were contested and NICE was taken to judicial review - by patients.

They were rejected by most patient groups for being too broad and recommending Cognitive Behaviour Therapy (CBT) and Graded Exercise Therapy (GET) as evidence based treatments.
ME/CFS NICE guidelines are being fully updated after a lot of pressure from patient groups and expected to be published in 2020.
[see also IiMER statements on NICE]

Oxford Criteria

A set of criteria created by and for psychiatrists - these criteria are far less rigorous and may include patients with fatigue as their only symptom.
As such it allows far too many possibilities of inclusion of non-ME patients and serves no useful purpose, other than to aid the assertions of psychiatric groups who see ME as a somatoform disorder.

They now serve no real useful or scientific purpose.

These criteria have been formally rejected by the US NIH P2P report and the Agency of Healthcare Research and Quality Report.

The RCPH Guidelines

These guidelines were published in 2004.

The evidence base was poor at the time and remains so.

Much of the paediatric research has concentrated on behavioural aspects of the disease and there are large gaps to be covered to understand fully paediatric ME.

Unfortunately, much of the published research has conflated chronic fatigue and CFS and ME all into one condition making life difficult for children and their families.



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