Oxford and 1994 Definitions

In 1991 the British invented the Oxford definition of CFS, which essentially just says the patient is tired.

In 1994, the CDC revisited the 1988 definition. Development of both CDC definitions occurred in response to a number of epidemic outbreaks in the U.S. Moreover, a number of clinicians had experienced groups of endemic cases within their practices.

Despite the careful clinical reporting which demonstrated a very similar organic pathophysiolgy of the both epidemic and endemic cases, the CDC chose to place a partially psychiatric emphasis on the illness. This bias led to the 1994 definition which was less evidence-based and more of a compromise between those who wished to characterize the illness largely as fatigue and somatization, and those who understood the illness to be primarily physical in nature.

As a compromise definition, it gave something to both views—thereby allowing for the proper diagnosis of many patients, but also for egregious misdiagnosis. Patients with psychiatric illness could be misdiagnosed as having the physical syndrome, or patients having the physical syndrome could be falsely diagnosed with psychiatric illness.

The consequences for either group of patients in obtaining either ineffectual or harmful treatment are immediately obvious.

It was during the 1990s that patients began calling the illness the Chronic Fatigue and Immune Dysfunction Syndrome (CFIDS)—pronounced SEE-fids.