Contrasting chronic fatigue syndrome versus myalgic encephalomyelitis/chronic fatigue syndrome

Abstract

Background: Much debate is transpiring regarding whether chronic fatigue syndrome (CFS) and myalgic encephalomyelitis (ME) are different illnesses. Several prior studies that compared the Fukuda et al. CFS criteria to the Canadian ME/CFS criteria found that the Canadian criteria identified patients with more functional impairments and greater physical, mental, and cognitive problems than those who met Fukuda et al. criteria. These samples were located in the Chicago metropolitan area, so the results could not be generalized to other locations. In addition, past studies used a symptom questionnaire that was not specifically developed to tap the Canadian criteria. Purpose: The present comparative study of CFS and ME/CFS criteria was intended to correct the limitations of prior studies. Methods: This article used data from three distinct samples to compare patients who met criteria for the ME/CFS Canadian clinical case definition to those who met the Fukuda et al. CFS case definition. Results: Findings indicated that fewer individuals met the Canadian criteria than the Fukuda et al. criteria. Those who met the Canadian criteria evidenced more severe symptoms and physical functioning impairment. Conclusions: Future research should continue to compare existing case definitions and determine which criteria best select for this illness.

Keywords:

• chronic fatigue syndrome
• myalgic encephalomyelitis/chronic fatigue syndrome
• Fukuda criteria
• Canadian clinical criteria

Acknowledgements

Requests for reprints should be sent to Leonard A. Jason, DePaul University, Center for Community Research, 990 W. Fullerton Ave., Chicago, IL 60614, USA. Funding was provided by NIAID (grant numbers AI 49720 and AI 055735). The CFIDS Association of America approved the use of de-identified SolveCFS BioBank registry data in this analysis. We appreciate the ME Research UK organization, which provided a grant to collect the Newcastle sample.

Notes on contributors

Leonard A. Jason is the Director of the Center for Community Research and Professor of Psychology at DePaul University.

Abigail Brown is currently a Graduate Research Assistant at the Center for Community Research at DePaul University.

Meredyth Evans is currently a Graduate Research Assistant at the Center for Community Research at DePaul University.

Madison Sunnquist is currently a Research Assistant at the Center for Community Research at DePaul University.

Julia L. Newton is the Dean of Clinical Medicine and Clinical Professor of Ageing and Medicine at Newcastle University in the UK.