Chronic Fatigue Syndrome versus Systemic Exertion Intolerance Disease.
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.


OBJECTIVE
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, Myalgic Encephalomyelitis (ME-ICC), Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), as well as a case definition developed through empirical methods.


METHODS
We used a cross-sectional design with samples from tertiary care settings, a biobank sample, and other forums. 796 patients from the US, Great Britain, and Norway completed the DePaul Symptom Questionnaire.


RESULTS
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.


CONCLUSIONS
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.
DePaul University.
Leonard A
LA
Jason
DePaul University.
Madison
M
Sunnquist
DePaul University.
Abigail
A
Brown
Newcastle University.
Julia L
JL
Newton
Oslo University Hospital.
Elin Bolle
EB
Strand
Solve ME/CFS Initiative.
Suzanne D
SD
Vernon
Myalgic Encephalomyelitis; Systemic Exertion Intolerance Disease; case definitions; chronic fatigue syndrome