Post by Ms B. on Oct 1, 2008 10:12:52 GMT 10
<-- That's my responseConstruct validity of chronic fatigue syndrome
Research of the ilk that follows and its associated hasty and misguided assumption lie at the core of the medical profession's ongoing misunderstanding and confusion with regard to accurately diagnosing and appropriately treating ME/CFS.
The emergence and acceptance of an insightful and accurate case definition of ME/CFS (similar to the highly lauded Canadian Case Definition 2003) is a prerequisite to broader understanding of the disease and with certainty must precede quality research into better and more appropriate treatment. Sadly, the following research summary replete with fingerprints of all the usual suspects is indicative of just how little progress has been made and how much further we have to go.
Ian Hickie, Tracey Davenport, Suzanne Vernon, Rosane Nisenbaum, William C. Reeves, Andrew Lloyd and the International Chronic Fatigue Syndrome Study Group*
From the Brain & Mind Research Institute, University of Sydney,
Sydney, NSW, Australia (I.H., T.A.D.), the Viral Exanthems and Herpesvirus Branch, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA (S.V., R.N., W.C.R.), and the School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia (A.L.). Current address: University of Toronto, Toronto, Canada (RN).
*The researchers who contributed data to this study included:
Professor Gijs Bleijenberg, Dr Sieberen P. van der Werf, Dr Judith B. Prins (University Medical Centre, Nijmegen, The Netherlands); Dr Paul M.A. Blenkiron (Bootham Park Hospital, York, United Kingdom); Professor Dedra Buchwald, Mr Wayne R. Smith (Harborview Medical Center, Washington, United States); Dr Rachel Edwards, Dr Sean Lynch (University of Leeds, Leeds, United Kingdom); Professor Laurence J. Kirmayer, Ms Suzanne S. Taillefer (McGill University, Quebec, Canada); Dr Sing Lee (Prince of Wales Hospital, Shatin, Hong Kong); Professor Nicholas G. Martin, Dr Nathan A. Gillespie (Queensland Institute of Medical Research, Queensland, Australia); Dr Shirley McIlvenny (Sultan Qaboos University, Sultanate of Oman, United Arab Emirates); Professor Norman Sartorius, Dr T.B. Ustun (World Health Organization); Dr Petros Skapinakis (University of Wales, Cardiff, United Kingdom); Professor Simon Wessely, Dr Trudie Chalder, Dr Matthew Hotoprolonged fatigue, Dr Chaichana Nimnuan, Ms Bridget Candy, Dr Lucy Darbishire, Dr Leone Ridsdale (Guy's, King's and St Thomas' School of Medicine, London, United Kingdom); Professor Peter D. White, Ms Janice M. Thomas (St Bartholomew's Hospital, London, United Kingdom); Associate Professor Kathleen Wilhelm, Mr Dusan Hadzi-Pavlovic, Dr Andrew Wilson(University of New South Wales, New South Wales, Australia).
Address correspondence to: Professor Ian Hickie, Brain & Mind Research Institute, P.O. Box M160, Missenden Road, NSW, 2050, Australia or at ianh@med.usyd.edu.au
ABSTRACT
Background: The development of the international consensus case definition for chronic fatigue syndrome (CFS) was a major advance for etiologic and treatment research. However, the construct validity of CFS and related prolonged fatigue syndromes across cultures and healthcare settings is still challenged.
Objective: To utilize international epidemiologic and clinical research datasets to test the construct validity of CFS.
Design: Relevant demographic, symptom, and diagnostic data were obtained from 14 international study sites in 21 countries, including 33 studies of subjects with fatigue lasting one to six months(prolonged fatigue), more than six months (chronic fatigue), or CFS. Common symptom domains were derived by factor analytic techniques and then compared across cultures, communities, and healthcare settings.
Subjects: Data was obtained from 37,724 subjects (20,845 women; 57%). Most data came from population-based studies (n=15,749; 42%), or studies in primary care (n=19,472; 52%) with only a small proportion being from referral clinics (n=2,503; n=6%). The sample included 2,013 subjects with chronic fatigue, and 1,958 with CFS.
Results: A five-factor model of the key symptom domains was optimal and stable across settings. The five factors were labelled: 'musculoskeletal pain / fatigue', 'neurocognitive difficulties', 'inflammation', and 'sleep disturbance / fatigue' and 'mood disturbance'. These empirically-derived symptom domains overlap closely with the key components of the diagnostic criteria for CFS.
Limitations: Comparison of the datasets relied upon assumptions regarding comparable symptom items.
Conclusion: The construct validity of CFS is largely supported by an empirically-derived factor structure from existing international datasets. Mood disturbance may be better considered a core, rather than a co-morbid, component of the syndrome. The CFS construct consists largely of symptom domains likely to reflect central nervous system dysfunction