What is the ICD?

The International Classification serves to record and report health and health-related conditions globally. ICD ensures interoperability of digital health data, and their comparability. The ICD contains diseases, disorders, health conditions and much more. The inclusion of a specific category into ICD depends on utility to the different uses of ICD and sufficient evidence that a health condition exists.

What is chronic fatigue syndrome?

Currently there is no consensus agreement amongst medical professionals as to how chronic fatigue syndrome may be definitively diagnosed. It may include chronic, profound, disabling, and unexplained fatigue with coinciding symptoms such as sleep problems or post-exertional malaise. 

In ICD-11, it is classified under Chapter 8: Diseases of the Nervous System, within the code 8E49 Postviral fatigue syndrome.  During the revision of ICD-11, a number of proposals were received arguing for the re-positioning of chronic fatigue syndrome from its current position to the Chapter 01: Certain infectious or parasitic diseases.

Literature review and findings

In response to the proposals, WHO conducted an extensive literature review of research relating to chronic fatigue. The review found that there remains insufficient evidence to classify chronic fatigue as an infectious disease, at this time. The review also confirmed the lack of consensus on a reliable diagnostic pattern of symptoms, the continued debate about etiology and the absence of any uniform or reliable treatment. The only constant in the studies reviewed was the lead symptom of ‘fatigue’, persistent over time.

Decision

As a result of the review, there is no change to the current placement of the term in ICD-11 and the category ‘post-viral fatigue’ that is the indexing target for inclusion of chronic fatigue was retained within Diseases of the Nervous system, until such a time as evidence justifies an alternative.