British criteria – American ME and CFS Society

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a poorly understood condition, apparently related to both psychiatric disturbance and infectious illness. Little progress has been made in identifying aetiology, owing to a lack of epidemiological studies using case-definition criteria.

METHOD: A community postal survey of a random sample of over 1000 patients registered at a local health centre comprised a fatigue questionnaire and the 12-item General Health Questionnaire (GHQ).

RESULTS: Total fatigue scores were modestly higher in women than men. Fatigue was most frequently attributed to psychosocial factors. Fatigue and GHQ scores were strongly correlated. Two men and two women satisfied British criteria for CFS, a prevalence of 0.56% (95% Cl 0.16-1.47%); three were probable psychiatric cases.

CONCLUSIONS: Previously reported sociodemographic associations of CFS may reflect medical referral patterns. A strong association exists with psychological morbidity, but relabelling CFS as a psychiatric disorder is not justified.

Source: Lawrie SM, Pelosi AJ. Chronic fatigue syndrome in the community. Prevalence and associations. Br J Psychiatry. 1995 Jun;166(6):793-7. http://www.ncbi.nlm.nih.gov/pubmed/7663830

Abstract:

BACKGROUND: Our goals were to determine the prevalence of unusual, debilitating fatigue and the frequency with which it was associated with the chronic fatigue syndrome (CFS) or other physical or psychological illness in an outpatient clinic population.

METHODS: We prospectively evaluated a cohort of 1000 consecutive patients in a primary care clinic in an urban, hospital-based general medicine practice. The study protocol included a detailed history, physical examination, and laboratory and psychiatric testing.

RESULTS: Five patients who came because of CFS studies were excluded. Of the remaining 995, 323 reported fatigue, and 271 (27%) complained of at least 6 months of unusual fatigue that interfered with their daily lives. Of the 271, self-report or record review revealed a medical or psychiatric condition that could have explained the fatigue in 186 (69%). Thus, 85 (8.5%) of 995 patients had a debilitating fatigue of at least 6 months’ duration, without apparent cause. Of these patients, 48 refused further evaluation, and 11 were unavailable for follow-up; 26 completed the protocol. Three of the 26 were hypothyroid, and one had a major psychiatric disorder. Of the remaining 22 patients, three met Centers for Disease Control and Prevention criteria for CFS, four met British criteria, and 10 met the Australian case definition. The point prevalences of CFS were thus 0.3% (95% confidence interval [CI], 0% to 0.6%), 0.4% (95% CI, 0% to 0.8%), and 1.0% (95% CI, 0.4% to 1.6%) using the Centers for Disease Control and Prevention, British, and Australian case definitions, respectively. These estimates were conservative, because they assumed that none of the patients who refused evaluation or were unavailable for follow-up would meet criteria for CFS.

CONCLUSIONS: While chronic, debilitating fatigue is common in medical outpatients, CFS is relatively uncommon. Prevalence depends substantially on the case definition used.

Source: Bates DW, Schmitt W, Buchwald D, Ware NC, Lee J, Thoyer E, Kornish RJ, Komaroff AL. Prevalence of fatigue and chronic fatigue syndrome in a primary care practice. Arch Intern Med. 1993 Dec 27;153(24):2759-65. http://www.ncbi.nlm.nih.gov/pubmed/8257251