Oxford criteria

The Oxford criteria are a set of criteria for the diagnosis Chronic Fatigue Syndrome published in 1991 by a group mostly consisting of psychiatrists, and was designed for research. They identify two broad syndromes and are used primarily for research purposes. The Oxford criteria was used for PACE trial participation.

Authors

Michael Sharpe, Len Archard, Jangu Banatvala, Leszek Borysiewicz, Anthony Clare, Anthony David, Richard Edwards, Keith Hawton, Harold Lambert, Russell Lane.

Definition

Chronic fatigue syndrome

• fatigue is the principal symptom; the fatigue is disabling, and affects physical and mental functioning, and should have been present for a minimum of 6 months during which it was present for more than 50% of the time.
• other symptoms may be present: particularly myalgia, mood swings and sleep disturbances.
• definite onset of symptoms, not life-long.
• exclusions: patients with established medical conditions known to produce chronic fatigue; also patients with a current diagnosis of schizophrenia, bipolar disorder (manic depressive illness), substance abuse, eating disorder or proven organic brain disease.

Post-infectious Fatigue Syndrome (PIFS)

A subtype of chronic fatigue syndrome which either "follows an infection or is associated with a current infection (although whether such associated infection is of aetiological significance (i.e. whether it is the cause of the symptoms) is a topic for research)".

To meet the research criteria for PIFS patients must:

• i. fulfil the criteria for CFS as defined above (i.e. the Oxford definition)
• ii. should also fulfil the following additional criteria:
• (a) There is definite evidence of infection at onset or presentation (a patient’s self-report is unlikely to be sufficiently reliable).
• (b) the syndrome is present for a minimum of 6 months after onset of infection.
• (c) the infection has been corroborated by laboratory evidence.

The infection associated with fatigue does not need to be a virus.

Oxford Definition CFS and PIFS

• A report - chronic fatigue syndrome: guidelines for research - Journal of the Royal Society of Medicine - Volume 84 February 1991 118-121

Criticisms

• 2017, How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?
  

"For every 15 patients selected under Oxford criteria, 14 will be false positives when compared to Canadian Consensus Criteria. The Pace trial and FINE trial used Oxford criteria."

"When studies using the broad Oxford criteria (Sharpe et al., 1991) were excluded, a virtual disappearance of effect for graded exercise therapy (GET), cognitive behaviour therapy (CBT) and other psychological therapies recommended by the NICE guidelines (National Institute for Health and Care Excellence (NICE), 2007) was revealed. "

• 2015, Diagnostic Methods for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop (Full Text)
  

"Consensus groups and researchers should consider retiring the Oxford case definition because it differs from the other case definitions and is the least restrictive, probably including individuals with other overlapping conditions"

• 2015, Treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Systematic Review for a National Institutes of Health Pathways to Prevention Workshop (Full Text)
  :"The Oxford CFS case definition is the least restrictive, and its use as entry criteria could have resulted in selection of participants with other fatiguing illnesses or illnesses that resolve spontaneously with time (16, 71)."

• Post-exertional malaise is not a listed symptom. When this symptom is not mandatory, patients with Chronic Fatigue and not the grossly misnamed disease Chronic Fatigue Syndrome are swept into the study.
• Depression is not an absolute exception for a possible cause of Chronic Fatigue (not to be confused with Chronic Fatigue Syndrome). This allows for patients with depression to be misdiagnosed with CFS.
• Many psychiatric disorders are not excluded, even though the disorder is designed for research. Although schizophrenia, substance abuse, bipolar disorder, eating disorders, and verified organic brain disorders are excluded from diagnosis in the Oxford criteria, anxiety disorders, depressive disorders, and hyperventilation can be included. This allows for a more heterogeneous patient sample which can render clinical study results indeterminate.

• US NIH Report Calls for UK Definition of ME/CFS to be Scrapped - The Argus Report By: Penny Swift.

Excerpt

The United States National Institutes of Health (NIH) has issued a draft report that highlights the dire need for scientific research that will help find a cure for the millions of people suffering from myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) worldwide. The report also highlights the fact that the decades-old UK Royal Society of Medicine’s Oxford criteria for ME/CFS are severely “flawed,” and that continuing to use these criteria may “cause harm.” Further, the NIH report says that the Royal Society definition should “be retired” and replaced with a single case definition agreed to by the ME/CFS community.

• 2017, Chronic Fatigue Syndrome prevalence is grossly overestimated using Oxford criteria compared to Centers for Disease Control (Fukuda) criteria in a U.S. population study (Full text)

Research using the Oxford criteria

• 2010: Psychiatric misdiagnoses in patients with chronic fatigue syndrome
  • "Conclusions: Doctors assessing patients in a chronic fatigue syndrome clinic miss psychiatric diagnoses more often than misdiagnosing them. Missed diagnoses are common. CFS clinic doctors should be trained to diagnose psychiatric disorders."

Learn more

• 2016, AHRQ Evidence Review Changes Its Conclusions

See also

• FINE trial
• PACE trial
• Biopsychosocial model
• Viral onset hypothesis
• Wessely school