Institute of Medicine (2015)
- Authors: Institute of Medicine, Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Board on the Health of Select Populations
- Institutes: Committee on the Diagnostic Criteria for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome; Board on the Health of Select Populations; Institute of Medicine.
- Publisher: The National Academies Press
- Link: Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness
Summary
This landmark report from the Institute of Medicine provides strong validation for the severity and legitimacy of ME/CFS, directly addressing the skepticism that patients often face. By proposing new diagnostic criteria centered on core, debilitating symptoms like post-exertional malaise, it provides clinicians with a clearer path to diagnosis, potentially reducing the years-long diagnostic delays many patients endure. The recommendation to rename the illness “systemic exertion intolerance disease” (SEID) is a direct attempt to reduce stigma and better reflect the central role of exertion intolerance in the disease’s pathology. For patients, this report represents a crucial step toward improved medical recognition, more accurate diagnoses, and a stronger foundation for future research into treatments.
What was researched?
This Institute of Medicine (IOM) report outlines the work of an expert committee charged with evaluating the numerous existing diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Based on a comprehensive evidence review, the committee’s objective was to develop new, evidence-based clinical diagnostic criteria, recommend whether a new name for the illness was warranted, and propose a strategy for disseminating their findings to healthcare professionals.
Why was it researched?
The study was commissioned because diagnosing ME/CFS is a persistent challenge, leading to long delays and a high rate of undiagnosed patients, estimated to be between 84 and 91 percent. Existing case definitions were numerous, varied, and often conflicting, causing confusion for clinicians and researchers. This situation, coupled with skepticism in the medical community, prompted the Department of Health and Human Services (HHS) to contract with the IOM to develop clearer, consensus-based criteria to improve the accuracy and timeliness of diagnosis and patient care.
How was it researched?
This was a consensus study based on a comprehensive literature review. The IOM convened a 15-member committee with expertise in ME/CFS and related fields. The committee systematically reviewed scientific literature published since 1950, heard testimony from patients, advocates, and scientific experts, and considered hundreds of public comments. An adapted “GRADE grid” was used to formally assess the evidence for various symptoms, and the final recommendations for new diagnostic criteria were reached through a consensus-building methodology among the entire committee.
What has been found?
The committee proposed new, more focused diagnostic criteria requiring three core symptoms: 1) a substantial reduction in pre-illness activity levels lasting more than 6 months, accompanied by profound, new-onset fatigue not alleviated by rest; 2) post-exertional malaise (PEM); and 3) unrefreshing sleep. In addition, a diagnosis requires at least one of two other manifestations: cognitive impairment or orthostatic intolerance. The committee also concluded that the name “chronic fatigue syndrome” is stigmatizing and trivializing, and that “myalgic encephalomyelitis” is not well supported by evidence; they recommended renaming the illness “systemic exertion intolerance disease” (SEID).
Discussion
The committee noted that a significant challenge in their work was the methodological limitations of the existing ME/CFS research base. They highlighted the heterogeneity in patient and control groups across studies, the use of many different and sometimes unvalidated measures for symptoms, and the lack of properly matched control groups (e.g., patients with other fatiguing illnesses). The committee was also struck by the overall paucity of research funding and studies conducted to date, which limited their ability to define disease subgroups or the natural history of the illness.
Conclusion & Future Work
The committee concluded that ME/CFS is a serious, chronic, complex, systemic disease and that their proposed evidence-based criteria will enable clinicians to make more accurate and timely diagnoses. They recommended that a multidisciplinary group should reexamine and update these new criteria in no more than 5 years, as new research becomes available. The report emphasizes that more research is essential to better understand the etiology, pathophysiology, and treatment of the disease.