Does the SEID Definition Pass Muster? Lenny Jason Reports


Founder of Health Rising and Phoenix Rising
Staff member
This is the study that would have been done during the deliberations for new definition - if Lenny Jason had chosen to join them. Since he didn't the IOM group had to come with a definition on their own. I'll have to read the study to understand. It's doesn't look like great news for the definition.

This study validates the great need there was to have our definition expert on the team. Jason said he could have run the analyses if he had been given the data and asserted they should have given him the data - even though it would have broken longstanding IOM protocol - possibly endangering the entire project. I propose a better solution was simply for him to have sat on the committee. This is his area of expertise, after all.

Chronic fatigue syndrome versus systemic exertion intolerance disease
Leonard A. Jason*, Madison Sunnquist, Abigail Brown, Julia L. Newton, Elin Bolle Strand & Suzanne D. Vernon
Fatigue: Biomedicine, Health & Behavior. Published online June 15

Background: The Institute of Medicine has recommended a change in the name and criteria for chronic fatigue syndrome (CFS), renaming the illness systemic exertion intolerance disease (SEID). The new SEID case definition requires substantial reductions or impairments in the ability to engage in pre-illness activities, unrefreshing sleep, post-exertional malaise, and either cognitive impairment or orthostatic intolerance.

In the current study, samples were generated through several different methods and were used to compare this new case definition to previous case definitions for CFS, the International Consensus Criteria for myalgic encephalomyelitis (ME-ICC), the Canadian myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) definition, as well as a case definition developed through empirical methods.

We used a cross-sectional design with samples from tertiary care settings, a BioBank sample, and other forums. Seven hundred and ninety-six patients from the USA, Great Britain, and Norway completed the DePaul Symptom Questionnaire.

Findings indicated that the SEID criteria identified 88% of participants in the samples analyzed, which is comparable to the 92% that met the Fukuda criteria. The SEID case definition was compared to a four-item empiric criteria, and findings indicated that the four-item empiric criteria identified a smaller, more functionally limited and symptomatic group of patients.

The recently developed SEID criteria appears to identify a group comparable in size to the Fukuda et al. criteria, but a larger group of patients than the Canadian ME/CFS and ME criteria, and selects more patients who have less impairment and fewer symptoms than a four-item empiric criteria.

Who Me?

Well-Known Member
I've noticed that people on forums now write ME/CFS/SEID

I still can't tell you what SEID stands for.


Founder of Health Rising and Phoenix Rising
Staff member
I was thinking I was going to have to explain to someone why I couldn't go on a hike with them and it occurred to me that stating I have systemic exertion intolerance disease - if that's what it is - was going to make it a heck of a lot easier than saying I had chronic fatigue syndrome

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