Nations have set up different standards for diagnosing ME/CFS. Researchers use different case definitions for their ME/CFS cohorts.
This has skewed some of the research so that results of some studies include people who have other illnesses, even psychiatric ones. This also means many with ME/CFS have been misdiagnosed or are not being diagnosed.
This is why, in 2003, an international group of leading researchers established a recommended diagnostic definition. Commonly called “The Canadian Consensus Criteria” (CCC). In the summer of 2011, 26 medical experts from around the globe made a revision and it is now called “International Consensus Criteria.” This is the most narrow definition that matches symptoms found in cases of the outbreaks of the disease in the U.S. and U.K.
Using this criteria for research, in addition to clinical diagnosis, will make sure psychiatric patients are not included in ME/CFS studies, which is necessary to get a true picture of the disease.
Distinctive Features of the ICC: This criteria does not include the requirement that the symptoms have lasted at least six months. Studies have shown that early diagnosis is important in long-term outcomes. Removing the six-month requirement also helps researchers find the cause.
Some of the symptoms below required:
According to this paper, someone who meets the criteria should be diagnosed with myalgic encephalomyelitis. Someone who has post-exertional neuroimmune exhaustion but does not have the required number of other symptoms would be diagnosed as atypical myalgic encephalomyelitis.
Quotes from the document:
“The label ‘chronic fatigue syndrome’ (CFS) has persisted for many years because of the lack of knowledge of the aetiological agents and the disease process. In view of more recent research and clinical experience that strongly point to widespread inflammation and multisystemic neuropathology, it is more appropriate and correct to use the term ‘myalgic encephalomyelitis’ (ME) because it indicates an underlying pathophysiology.” – Abstract
“The problem with broadly inclusive criteria is that they do not select homogeneous sets of patients….Patient sets that include people who do not have the disease lead to biased research findings, inappropriate treatments and waste scarce research funds.” – Introduction
“No other disease criteria require that diagnoses be withheld until after the patient has suffered with the affliction for 6 months.” – International Consensus Criteria
“Using ‘fatigue’ as a name of a disease gives it exclusive emphasis and has been the most confusing and misused criterion. No other fatiguing disease has ‘chronic fatigue’ attached to its name – e.g. cancer/chronic fatigue, multiple sclerosis/chronic fatigue – except ME/CFS.” – International Consensus Criteria