The CFS case definition currently in use has been defined by the CDC, Fukuda et al., 1994. This definition was presented as a means intended for research. A first set of criteria, [Holmes et al., Ann Intern Med 1988; 108:387-9] was hereby revised and replaced.
A study comparing the two CFS-definitions found the 1988-definition more likely to include cases arisen as infectious diseases, Arpino et al., 1999., and to be more disabled and longtime sufferers, De Becker et al., 2001, and Jason et al., 2001.
Diagnostic criteria set by Trans-NIH working group for research on CFS, diagnostic.criteria.NIH06.txt. Dr. Reeves (the CDC) answers questions relating to the current CFS definition, reeves.etal06.txt.
A pediatric case definition for ME and CFS, jason.etal06.txt.
The amount of scientific literature on CFS/ME has not grown at a pace comparable to that on FM. The apparent stagnation over the past decade suggests that if this domain of research is to survive, aggressive efforts may be required to promote a more inclusive case definition, friedberg.etal07.txt,friedberg.etal.07.txt, friedberg.etal07.pdf.
Recently an epidemiological definition was proposed, osoba.etal07.txt.
In 1991 psychiatrists (of British origin mainly) lauched their own CFS-criteria, the Oxford criteria [Sharpe et al., J R Soc Med, 1991 Feb; 84(2):118-21], oxford.criteria91.txt. By this criteria CFS is defined less strict omitting the 8 minor criteria required by the CDC-definition, including patients with fatigue as their only symptom (e.g. psychiatric patients). The absurd situation imposed by this psychiatric CFS case definition is brilliantly enlightened, Jason et al., 1997.
A discussion on the importance of the CDC-defined diagnosis compared to the absence of symptoms other than fatigue, letter.stouten04.txt, letter.stouten04.pdf reply, letter.bleijenberg.etal04.txt, letter.bleijenberg.etal04.pdf.
2003 – Canadian Case Criteria for CFS
A Canadian clinical working case definition for CFS was published in 2003, ME/CFS, Canadian clinical definition, 2003, Carruthers et al., 2003, Carruthers et al., 2003 (pdf). The editorial in connection with the new guidelines, editorial, JCFS, 2003. A short summary of the Canadian guidelines, carruthers.etal.short03.txt and canadian.guidelines.summary04.txt. The Canadian guidelines request laborious testing, a problem in clinical practice according to Dr. Shepherd, comment.canadian.guidelines04.txt.
The Nightingale Definition of Myalgic Encephalomyelitis (M.E.), nightingale.definition06.txt, Definitions and aetiology of Myalgic Encephalomyelitis (ME): how the Canadian Consensus Clinical Definition of ME Works, carruthers06.txt.
Comparing the Fukuda et al. criteria and the Canadian Case Definition for CFS, jason.etal04.txt, jason.etal04.pdf, d Both definitions select individuals who are significantly different from psychiatric controls with chronic fatigue, and the Canadian criteria select cases with less psychiatric co-morbidity, more physical functional impairment, and more fatigue/weakness, neuropsychiatric, and neurological symptoms.
The NICE trial in the UK does not stick to strict CFS diagnostic criteria, cfs-definition07.txt.
Future CFS Definition(s)
Identification of ambiguities in the 1994 CFS research case definition and recommendations for resolution, reeves.etal03.txt, reeves.etal03.pdf. The Swedish CFS research team’s results raise fundamental questions about the 1994 Centers for Disease Control criteria as (1) there was no empirical support for the requirement of four of eight cardinal CFS symptoms; (2) these eight symptoms were not equivalent in their capacity to predict fatigue; and (3) no combination of symptoms was markedly more heritable, sullivan.etal05.txt, sullivan.etal05.pdf.
Three methods for improving the 1994 CDC-diagnostic criteria: identification of new diagnostic symptoms, the use of severity ratings for symptomatology, and the identification of standardized measures that differentiate cases of CFS from other conditions, king.jason04.txt, king.jason04.pdf.
Is there a test for CFS ?
An unverified spectroscopic diagnosis of CFS in serum samples has been suggested, sakudo.etal06.txt, sakudo.etal.06.txt, sakudo.etal06.pdf. With FM unverified findings of urine markers, ribel-madsen.etal07.txt.
CFS in International Classification of Diseases (ICD)
CFS is classified (coded) in WHO’s (1992) ICD-10 (International Classification of Diseases) as G93.3, a subcategory under diseases of the brain, (i.e. a neurological disease). On the classification issue following a WHO note 23 Jan 2004, who.classification.us04.txt. The WHO website on this issue, who.guide.online.link04.txt.
In the US a modification of the previous WHO coding ICD-9, a so called ICD9-CM is still in use (CM “Clinical Modifications”). This results in difficulties in relation to CFS, as this disease is not covered by the ICD-9. However, the US has adopted the ICD-10 (including clinical modifications) supposedly to be in use by 2004. A short note on the classification of CFS and ME by the WHO, codes.who.explanation04.txt.
An alternative to WHO, e-medicine classification, e-medicine.cfs07.txt.
CFS/ ME in UK Classification
In 2004 the British WHO-associated office finally accepted the correct CFS/ ME code as G93.3, who.coding.cfs.me04.txt. Dr. Charles Shepherd wrote to the UK National Health Service to make this institution change its information on the coding question, classification.cfs.complaint04.txt. The correct WHO classification of CFS is now a fact even in the UK as shown by their statement 24, Jan 2004, who.classification.me.cfs04.txt. Some interesting considerations over the ME-term endings “itis” and “pathy”, who.classification.consideration04.txt.
Problems may arise in the future if WHO supports a “wider” fatigue definition as opposed to a “narrow” fatigue definition. This relates to the future ICD-11 coding of CFS, Skapinakis et al., 2003, Skapinakis et al., 2003 (pdf).