Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem and often long-lasting disorder, with manifestations that can cause substantial morbidity and can severely impair patients’ health and well-being. It is estimated that between 836 000 and 2.5 million individuals are affected in the United States.1,2 Patients with ME/CFS are typically unable to perform their normal activities, and as many as one-fourth are homebound or bedridden, sometimes for extended periods.3 As a result, the personal and social effects and ramifications of this disease are enormous.
However, ME/CFS is poorly accepted and poorly understood, and the characteristics necessary to make the diagnosis are contested. Patients’ concerns are often met with dismay and skepticism, if not outright dismissal. Clinicians, in turn, are confronted by competing definitions, which were usually developed for research and are quite complex and difficult to implement in a busy clinical practice. Patients who are fortunate enough and persistent enough to receive a correct diagnosis frequently report long delays before their disorder was identified. It is almost certainly the case that the majority of affected patients are never diagnosed. This is unfortunate because effective symptom management is often available, whereas the wrong interventions can make symptoms worse.
Making the diagnosis is essential for providing appropriate care. To that end, the Department of Health and Human Services (HHS), together with the National Institutes of Health, US Social Security Administration, US Food and Drug Administration, Centers for Disease Control and Prevention, and Agency for Healthcare Research and Quality, tasked the Institute of Medicine (IOM) to develop “evidence-based clinical diagnostic criteria for ME/CFS for use by clinicians, using a consensus-building methodology,” with input from patients and clinicians; to “recommend whether new terminology for ME/CFS should be adopted”; and to create plans for disseminating these conclusions to clinicians.