Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is very real, but the lack of a universally accepted definition of the complex, multifaceted condition is stifling progress with respect to optimizing patient care, according to a panel convened by the National Institutes of Health.
“A team of stakeholders (such as patients, clinicians, researchers, and federal agencies) should be assembled to reach a consensus on the definition and variables of ME/CFS. A national and international research network should be developed to clarify the case definition and advance the field,” the Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome panel stated in a position paper (Ann. Intern. Med. 2015 June 15 [doi:10.7326/M15-0338]).
The panel specifically recommended that the Oxford case definition of ME/CFS be retired, as it “may impair progress and cause harm, ” and it further recommended that “the ME/CFS community concur on a single case definition (even if it is not perfect), and patients, clinicians, and researchers agree on a definition for meaningful recovery.”
The ME/CFS definition recommendation is one of seven that emerged from the December 2014 workshop, which was cosponsored by the NIH Office of Disease Prevention and the Trans-NIH ME/CFS Research Working Group.
The workshop agenda was developed by a multidisciplinary working group, and discussion was facilitated by input from invited experts, public comment by various stakeholders, and by systematic evidence-based reviews on the diagnosis and treatment of ME/CFS that were conducted expressly for the workshop by the Pacific Northwest Evidence-based Practice Center, Portland, Ore., with the support of the Agency for Healthcare Research and Quality.
The diagnostic methods and treatment reviews also were published June 15 in the Annals of Internal Medicine.
The diagnostic methods review identified nine sets of clinical criteria for defining ME/CFS from articles published between 1998 and 2013, according to Dr. Elizabeth Haney of Oregon Health and Science University, Portland, and her colleagues.
The review authors noted that none of the nine methods – including one recently proposed by the Institute of Medicine that includes elements of the previous definitions and which also proposed changing the name of ME/CFS to systemic exertion intolerance disease – have been adequately tested to identify affected patients in the setting of diagnostic uncertainly (Ann. Intern. Med. 2015 June 15 [doi:10.7326/M15-0443]).
The treatment review identified trials showing a low to moderate benefit with rintatolimod, counseling therapies, and graded exercise therapy for some patients who met case definitions for ME/CFS but found that those treatments have not been adequately tested in broader patient populations and that evidence is insufficient for numerous other treatments, according to Dr. M.E. Beth Smith, also of Oregon Health and Science University, and her colleagues.
“More definitive studies are needed to fill these research gaps,” the authors wrote (Ann. Intern. Med. 2015 June 15 [doi:10.7326/M15-0114]).
During a press briefing on the workshop panel’s conclusions and recommendations, workshop and panel chair Dr. Carmen R. Green said that ME/CFS is a chronic, complex, multifaceted condition characterized by extreme fatigue, pain, impaired memory, sleep disturbance, and insomnia, which are not improved by rest.
The cause and pathogenesis of ME/CFS remains unknown, and no laboratory diagnostic tests or known cures exist, said Dr. Green of the University of Michigan Health System, Ann Arbor.
Panel member Dr. Kathleen M. O’Neil added that the panel heard of hundreds of combinations of nonspecific symptoms common to both ME/CFS and other diseases, and that very little agreement exists on the constellation of signs and symptoms associated with ME/CFS.
“There has been a lot of confusion, and there are a lot of well-intentioned, but eventually misguided, issues in assessing and treating these patients, who are so very needy,” said Dr. O’Neil of the University of Indiana, Indianapolis.
In its report, the panel also noted that about 1 million persons – mostly women– are affected, and that the syndrome represents an “unmet public health issue with an estimated economic burden between $2 billion and $7 billion in the United States.
“Limited knowledge and research funding create an additional burden for patients and health care providers. The research and health care community has frustrated its constituents by not appropriately assessing and treating the disease and by allowing patients to be stigmatized,” the panel wrote.
In addition to better defining ME/CFS, the panel had several other recommendations:
• Create new knowledge by investing in bench-to-bedside research for ME/CFS with an emphasis on developing biomarkers and diagnostic tests.
• Improve methods and measures to identify ME/CFS that “include the patient’s voice through patient-reported outcomes.”
• Provide training and education to clinicians, many of whom do not fully understand ME/CFS.