ME/CFS Primer/Education Bulletins 2009 Severe ME/CFS in Adults - A report from the CHROME Database
IACFS/ME Bulletin


Severe ME/CFS in Adults - A report from the CHROME Database

Derek Pheby1*, Peter Sneddon2, Inge Heinrich3

1Derek Pheby, BSc, MB,BS, LLM, MPhil, FFPH, Project Coordinator, National ME Observatory Visiting Professor, Faculty of Society and Health, Buckinghamshire New University, 106, Oxford Road, Uxbridge, Middlesex, UB8 1NA, UK
Tel.: +44 (0)1722 331283
e-mail :

2Dr. Peter Sneddon, M.A., PhD. School of Health and Social Sciences, Middlesex University and CHROME Research Group
7 Wilderton Road, London, N16 5QY, UK
e-mail :

3Dr. Inge Heinrich, MSc, PhD, Medical Statistician (retired),
“Thurne”, Gore Road, Eastry, Sandwich, Kent, CT13 0LP, UK. e-mail :


BACKGROUND:    Case History Research on ME (CHROME) was established in 1994 to undertake research on severely affected patients. Since 1995 CHROME has collected data on volunteers with severe ME/CFS. All are medically diagnosed, conform to Fukuda criteria, are or were house-bound, and ill for at least two years. Participants complete initial and annual follow-up questionnaires, and report their condition at onset of illness, a year previously, on recruitment, and annually thereafter.

METHOD:    We report symptom severity and ability to undertake activities of daily living in 324 participants recruited between 1995 and 1998, their evolution through time, and, for later onset (age 17+) subjects, changes occurring between recruitment and the latest questionnaire. Significance was assessed using the McNemar test or its binomial equivalent. RESULTS:    For most features, subjects deteriorated between onset and recruitment, with subsequent improvement, often slow and uneven, among later onset cases. Complete recovery was unusual. There were marked individual variations, and many subjects remained severely incapacitated or deteriorated. All features examined were more prevalent and severe in patients with a younger age of onset. Age at onset was bimodal, with peaks at 11-20 and 31-40. Most subjects, at recruitment, had been ill for 2-10 years. The proportion of early onset cases rose significantly in the mid-1980s.

CONCLUSIONS:    Caution is necessary in interpreting the results, given problems of self- selection, recall bias, and subjective interpretations of symptom ratings. It is unclear whether the reported trends are inevitable features of ME/CFS, or perhaps due to poor management at the outset.


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