Annals of Epidemiology, Volume 14, Issue 2 , February 2004, Pages 95-100
Authors: Gwen Kennedy PhD, [*] , Neil C. Abbot MSc, PhD, Vance Spence PhD, Christine Underwood MBChB and Jill J. F. Belch MD
Affilition: From the Vascular Diseases Research Unit, University Department of Medicine, Ninewells Hospital & Medical School, Dundee, UK
Received 9 June 2003; accepted 1 October 2003. ; Available online 7 January 2004.
Purpose: The Centers for Disease Control (CDC)-1994 definition of chronic fatigue syndrome (CFS) is very broad, and there have been suggestions that it lacks specificity. To test this, we have compared three groups of patients, all of whom fulfill the criteria but self-report different etiologies.
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Methods: Patients with self-reported symptoms which developed sporadically (sCFS, n = 48); after Gulf War service (GW, n = 24); and following exposure to organophosphate insecticides (OP, n = 25) underwent a clinical examination, completed the MOS SF-36 quality of life and Hospital Anxiety and Depression scales, and were assessed for major and minor criteria for CDC-1994 CFS.
Results: Significant differences in simple clinical measures and outcome measures were observed between groups. The GW group had significantly more severe physical symptoms––fatigue, muscle and multi-joint pain––than OP or sCFS, and the sCFS group was significantly less impaired than the other two groups in terms of role emotional and mental health. In all three groups, a majority of patients exhibited muscle weakness in the lower limbs, and significant numbers of patients had absent or abnormal reflexes.
Conclusions: Differences in simple, easily performed clinical outcome measurements can be observed between groups of patients, all of whom fulfill the CDC-1994 criteria for CFS. It is likely that their response to treatment may also vary. The specificity of the CFS case definition should be improved to define more homogeneous groups of patients for the purposes of treatment and research.
Author Keywords: Chronic Fatigue Syndrome; Case Definition; Quality of Life
Abbreviations: CFS, chronic fatigue syndrome; CDC, Centers for Disease Control; sCFS, sporadic developed chronic fatigue syndrome; GW, Gulf War; OP, organophosphate insecticides; HADS, Hospital Anxiety and Depression Scale
[*] Corresponding author. Address correspondence to: Dr. Gwen Kennedy, Vascular Diseases Research Unit, University Department of Medicine, Ninewells Hospital & Medical School, Dundee DD1 9SY, UK. Tel: 1382-632432; Fax: 1382-632333.
This study was supported by a grant from MERGE (Myalgic Encephalomyelitis Research Group for Education and Support, registered UK charity number 1080201), Perth PH1 5PP, Scotland, UK. J.J.F.B. receives funding from the Sir John Fisher Foundation.
Copyright © 2004 Elsevier Inc. All rights reserved.