Consensus Criteria for Myalgic Encephalomyelitis Research
Study shows preference for ICC and CCC
A recent study from Leonard A. Jason of the Center for Community Research at DePaul University in Chicago (USA) and Suvetha Ravichandran and Aiden Rathmann looked into whether there might be a consensus about research criteria for ME and ME/CFS case definitions. The paper, Can a consensus occur on a research case definition for ME/CFS?, states:
“To determine if there might be a consensus among patients, healthcare workers, and researchers, a brief questionnaire was distributed to an international group of patients to assess key issues involving ME and ME/CFS case definitions.”
Results included the following:
“Considerable support occurred for the ME-ICC (Myalgic Encephalomyelitis-International Consensus Criteria) and the Canadian Consensus Criteria (CCC), whereas the Fukuda Criteria received the least support.”
I am only able to read the abstract as the rest of the paper is behind a paywall. So my comments are based on that information.
Importance of using the ICC for ME Research
The International Consensus Primer (ICP) for ME (based on the ME-ICC from 2011) was written in 2012 by many of the same people who wrote the CCC in 2003. The ICP on page ii states:
“The ICC advance the successful strategy of the Canadian Consensus Criteria (CCC) of grouping coordinated patterns of symptom clusters that identify areas of pathology.”
They go on to explain the usefulness of the ME-ICC for researching:
“The logical way to advance science is to select a relatively homogeneous patient set that can be studied to identify biopathological mechanisms, biomarkers and disease process specific to that patient set, as well as comparing it to other patient sets.
It is counterproductive to use inconsistent and overly inclusive criteria to glean insight into the pathophysiology of ME if up to 90% of the research patient sets may not meet its criteria (Jason 2009).
Research on other fatiguing illnesses, such as cancer and multiple sclerosis (MS), is done on patients who have those diseases. There is a current, urgent need for ME research using patients who actually have ME.”
They clarify the importance of using ME-ICC research for confirmation of previous studies:
“When research is applied to patients satisfying the ICC, previous findings based on broader criteria will be confirmed or refuted. Validation of ME being a differential diagnosis, as is multiple sclerosis (MS), or a subgroup of chronic fatigue syndrome, will then be verified.”
They explain that those diagnosed with ME/CFS need to be thoroughly screened using ME-ICC.
“Patients diagnosed using broader or other criteria for CFS or its hybrids (Oxford, Reeves, London, Fukuda, CCC, etc.) should be reassessed with the ICC.”
NOTE: When the ME-ICC was written, ME/CFS was defined by the CCC. The current use of the label ME/CFS often refers to the CDC’s definition based on the IOM/NAM report from 2015. As this is even broader than the CCC, it is important to make sure patients with any ME/CFS diagnosis are screened using the ME-ICC. ME/CFS from the IOM/NAM report is a clinical criteria and not meant to be used for research.
Research into patients who fit into multiple categories has led to inaccurate and confusing research results. I have ME, so I want to see research that applies to my situation.
According to these experts, not everyone diagnosed using the ME/CFS criteria are appropriate to be used in ME research. To understand how ME/CFS has multiple meanings, see my article ME/CFS is an Umbrella Term.
Atypical ME
Researchers should also be made aware that there is an atypical ME designation that is useful for clinical care, but is not recommended for inclusion in studies.
From the International Consensus Criteria diagnostic criteria:
“Atypical myalgic encephalomyelitis: meets criteria for post-exertional neuroimmune exhaustion but has a limit of two less than required of the remaining criterial symptoms. Pain or sleep disturbance may be absent in rare cases.”
“Patients should meet the full criteria for epidemiological studies. If specific subgroups or atypical ME are included in a research study, that should be clearly indicated.”
Why was the CCC recommended by respondents?
I suspect some respondents to the survey didn't realize the ME-ICC is an updated version of the CCC created specifically for research. I think if there was more widespread understanding, the ME-ICC would have been selected as preferred for all ME research.
Many researchers are already utilizing the ME-ICC as can be seen in the list of studies found HERE.
As there is valuable research using the CCC, we also track those studies found HERE. My hope is that the most promising of these studies will be repeated using patients selected who are diagnosed using the ME-ICC.
Moving the field forward
Please help spread the word about the International Consensus Criteria. An easy way to do that is to share the collaborative document, ME-ICC Info Table of Contents. This list of resources is from the ME-ICC Info group on Facebook. (I am an admin in that group.) It has links to information about the ME-ICC in multiple languages.
Ask your doctor to confirm the diagnosis of ME using the Personalized Assessment and Diagnosis guidance starting on page 6 of the ME-IC Primer. This will help researchers with the screening process.
I think that the more everyone understands the usefulness of the ME International Consensus Criteria, the faster we will have community support and better treatment options to manage myalgic encephalomyelitis while we wait for a cure.
Colleen
Sources:
Leonard A. Jason, Suvetha Ravichandran & Aiden Rathmann (2024) Can a consensus occur on a research case definition for ME/CFS?, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2024.2314409
The National Library of Canada Cataloguing-in-Publication Data: Myalgic Encephalomyelitis – Adult & Paediatric: International Consensus Primer for Medical Practitioners. ISBN 978-0-9739335-3-6 https://drive.google.com/file/d/1A0Bvtl4xRUkP3fEJSGMujdPaqQ1-QCIE/view
Carruthers, B.M., van de Sande, M.I., De Meirleir, K.L., Klimas, N.G., Broderick, G., Mitchell, T., Staines, D., Powles, A.C.P., Speight, N., Vallings, R., Bateman, L., Baumgarten-Austrheim, B., Bell, D.S., Carlo-Stella, N., Chia, J., Darragh, A., Jo, D., Lewis, D., Light, A.R., Marshall-Gradisbik, S., Mena, I., Mikovits, J.A., Miwa, K., Murovska, M., Pall, M.L. and Stevens, S. (2011), Myalgic encephalomyelitis: International Consensus Criteria. Journal of Internal Medicine, 270: 327-338. https://doi.org/10.1111/j.1365-2796.2011.02428.x