The diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is complex and largely based on self-reported symptom profiles. The field lacks consensus for a singular case definition and heterogeneous samples make comparability across studies difficult.
The present study sought to validate a comprehensive self-report measure of ME/CFS symptomatology to aid in clinical and research assessment.
Exploratory factor analysis (EFA) was used to establish the underlying factor structure of the DePaul Symptom Questionnaire (DSQ) using a well-characterized sample of individuals (92.6% met the Fukuda et al. criteria and/or the Clinical Canadian Criteria) and this structure was then tested on a less stringently recruited sample of individuals utilizing a confirmatory factor analysis (CFA). Convergent and discriminant validity of the DSQ were also examined utilizing alternative measures of symptomatology and functioning.
A three-factor solution was found using EFA (Neuroendocrine, Autonomic, and Immune Symptoms; Neurological/Cognitive Dysfunction; Post-Exertional Malaise) and the fit of this factor structure was adequate for the second sample. The DSQ was found to have good convergent and discriminant validity.
The DSQ is a valid tool for assessing ME/CFS symptoms. There may be two core ME/CFS symptom clusters: post-exertional malaise and cognitive dysfunction.
Validating a measure of myalgic encephalomyelitis/chronic fatigue syndrome symptomatology by Abigail A. Brown & Leonard A. Jason in Fatigue: Biomedicine, Health & Behavior Volume 2, Issue 3, 2014