Patients diagnosed with Myalgic encephalomyelitis/chronic fatigue syndrome also fit systemic exertion intolerance disease criteria
Lily Chua, Jane L. Norrisa, Ian J. Valenciab and Jose G. Montoyaa
aStanford ME/CFS Initiative, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA;
bFormerly of Stanford ME/CFS Initiative, Division of Infectious Diseases and Geographic Medicine, Stanford University School of Medicine, Stanford, CA, USA
ABSTRACT
Background:
Myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) remains undiagnosed in up to 91% of patients. Recently, the United States-based Institute of Medicine (IOM) developed new diagnostic criteria, naming it systemic exertion intolerance disease (SEID).
Purpose:
We examined how subjects fit SEID criteria and existing ME/CFS case definitions early in their illness.
Methods:
A total of 131 subjects fitting 1994 Fukuda CFS criteria at the time of study recruitment completed a survey of symptoms they experienced during their first 6 months of illness.
Symptoms were drawn from SEID and existing criteria (1994 Fukuda, 2003 Canadian Consensus Criteria (CCC), and 2011 Myalgic Encephalomyelitis-International Consensus Criteria (ME-ICC)).
We calculated and compared the number/percentage of subjects fitting single or combinations of case definitions and the number/ percentage of subjects with SEID experiencing orthostatic intolerance (OI) and/or cognitive impairment.
Results:
At 6 months of illness, SEID criteria identified 72% of all subjects, similar to when Fukuda criteria (79%) or the CCC (71%) were used, whereas the ME-ICC selected for a significantly lower percentage (61%, p < .001).
When severity/frequency thresholds were added to the Fukuda criteria, CCC and ME-ICC, the percentage of these subjects also fitting SEID criteria increased to 93%, 97%, and 95%.
Eighty-seven percent of SEID subjects endorsed cognitive impairment and 92%, OI; 79% experienced both symptoms.
Conclusions:
SEID criteria categorize a similar percentage of subjects as Fukuda criteria early in the course of ME/CFS and contain the majority of subjects identified using other criteria while requiring fewer symptoms.
The advantage of SEID may be in its ease of use.
ARTICLE HISTORY
Received 24 May 2016
Accepted 21 February 2017
KEYWORDS Systemic exertion intolerance disease (SEID); Myalgic encephalomyelitis (ME); chronic fatigue syndrome (CFS); diagnosis; Canadian Consensus Criteria (CCC); Myalgic encephalomyelitis – international consensus criteria (ME-ICC)