To exercise or not to exercise in chronic fatigue syndrome?

To the Editor: The claim in Lloyd’s editorial1 that “the criteria for diagnosis are well accepted internationally” ignores the recent publication of the Canadian consensus guidelines for the diagnosis and management of myalgic encephalomyelitis/chronic fatigue syndrome,2 which were sponsored by Health Canada and written by an international group of well published researchers. The Canadian definition of chronic fatigue syndrome (CFS) requires the concurrent presence for six months of fatigue, post-exertional fatigue, sleep dysfunction, pain (including headaches) and neurological/cognitive manifestations, as well as at least one symptom from two of autonomic, neuroendocrine and immune manifestation categories (pp 12–13). These requirements add clinical specificity to the Fukuda criteria and exclude subjects who may have chronic fatigue for other reasons, such as psychiatric disorder without multiple physical symptoms.

Lloyd refers to the “recent refinements to improve reliability” in the revision of the research case definition by Reeves et al.3 The SPHERE screening instrument recommended by that article was designed for psychiatric screening in primary care. It arbitrarily classifies people with multiple physical symptoms, often severe in degree and associated with major disability, as having somatisation disorder. This is akin to subclassifying people with severe multiple sclerosis as having somatoform disorder and those with fewer and less severe symptoms as the “core” multiple sclerosis group, a finding which is not supported by the evidence.

Conclusions from the article by Wallman et al4 cannot be generalised to the severely ill. Recruitment was from “notices placed in medical surgeries and by advertisements in local newspapers”. Patients with severe CFS, who can barely venture outside their homes and are often too ill to read, would be unlikely to participate. Loblay, Chair of the Royal Australasian College of Physicians Working Group for CFS Clinical Practice Guidelines, urges caution about generalising from exercise studies, which never include people with severe CFS: “All these studies involve people willing and able to participate. The people who find it makes them feel lousy drop out.”5

Lloyd asserts exercise is no longer a question (“. . . graded physical exercise should become a cornerstone of the management approach for patients with CFS”). To promote such a strong, unqualified message to busy general practitioners who may be unfamiliar with the range of severity in CFS risks serious harm to patients.