Dear Secretary Sebelius,
We are writing as biomedical researchers and clinicians with expertise in the disease of Myalgic
Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) to inform you that we have reached a
consensus on adopting the 2003 Canadian Consensus Criteria (CCC) as the case definition for
this disease.
The 1994 International Case Definition (Fukuda et al, 1994), commonly known as the Fukuda
definition, was the primary case definition for ME/CFS for almost two decades. However, in
recent years expert researchers and clinicians have increasingly used the CCC, as they have
recognized that the CCC is a more scientifically accurate description of the disease.
The CCC was developed by an international group of researchers and clinicians with significant
expertise in ME research and treatment, and was published in a peer-reviewed journal in 2003
(Carruthers et al, Journal of Chronic Fatigue Syndrome, 2003). Unlike the Fukuda definition, the
more up-to-date CCC incorporates the extensive scientific knowledge gained from decades of
research. For example, the CCC requires the symptom of post-exertional malaise (PEM), which
researchers, clinicians, and patients consider a hallmark of the disease, and which is not a
mandatory symptom under the Fukuda definition. The CCC was endorsed in the Primer for
Clinical Practitioners published by the International Association of Chronic Fatigue Syndrome/
Myalgic Encephalomyelitis (IACFSME). This organization is the major international professional
organization concerned with research and patient care in ME/CFS.
The expert biomedical community will continue to refine and update the case definition as
scientific knowledge advances; for example, this may include consideration of the 2011 ME
International Consensus Criteria (Carruthers et al, Journal of Internal Medicine, 2011). As
leading researchers and clinicians in the field, however, we are in agreement that there is
sufficient evidence and experience to adopt the CCC now for research and clinical purposes,
and that failure to do so will significantly impede research and harm patient care. This step will
facilitate our efforts to define the biomarkers, which will be used to further refine the case
definition in the future.
We strongly urge the Department of Health and Human Services (HHS) to follow our lead by
using the CCC as the sole case definition for ME/CFS in all of the Department’s activities
related to this disease.
In addition, we strongly urge you to abandon efforts to reach out to groups such as the Institute
of Medicine (IOM) that lack the needed expertise to develop “clinical diagnostic criteria” for
ME/CFS. Since the expert ME/CFS scientific and medical community has developed and
adopted a case definition for research and clinical purposes, this effort is unnecessary and
would waste scarce taxpayer funds that would be much better directed toward funding research
on this disease. Worse, this effort threatens to move ME/CFS science backward by engaging
non-experts in the development of a case definition for a complex disease about which they are
not knowledgeable.